Leading with Knowledge: The Role of a Knowledge Management Officer in the Army

Introduction: The Significance of Knowledge Management in the Army

In the ever-evolving landscape of military operations, the ability to manage and leverage knowledge effectively has become a cornerstone of success. Knowledge management (KM) in the Army is not just about storing information; it’s about transforming data into actionable insights that drive decision-making and operational excellence. The role of a Knowledge Management Officer (KMO) emerges as a pivotal force in this process, ensuring that critical information flows seamlessly across teams, units, and command structures.

Modern military environments demand agility, precision, and a unified understanding of objectives. This is where KMOs shine. By creating systems that foster collaboration and ensure the right knowledge reaches the right people at the right time, they enable the Army to adapt swiftly to challenges. Whether it’s coordinating logistics, refining strategies, or enhancing training programs, KMOs are the architects of a smarter, more connected force.

But why is this so significant? The answer lies in the complexity of today’s missions. From humanitarian aid to combat scenarios, the Army operates in multifaceted environments where outdated or siloed information can lead to inefficiencies—or worse, mission failure. Knowledge management bridges these gaps, aligning resources, expertise, and objectives to ensure cohesive action. In essence, it transforms knowledge into a strategic weapon, one that can determine the outcome of critical operations.

The Key Responsibilities of a Knowledge Management Officer (KMO)

The role of a Knowledge Management Officer (KMO) is far from a passive one; it is dynamic, multifaceted, and deeply embedded in the operational heartbeat of the Army. A KMO is not merely a custodian of information but a strategist who ensures that knowledge flows efficiently and effectively across the organization. Their responsibilities are diverse, yet each task they undertake is geared toward one overarching goal: empowering the Army to act with precision and foresight.

Here are the core responsibilities of a KMO:

• Developing Knowledge Strategies: KMOs design and implement frameworks that align knowledge-sharing practices with the Army’s mission objectives. This involves creating guidelines, processes, and tools that ensure information is accessible and actionable.
• Facilitating Collaboration: They act as connectors, breaking down silos between units and fostering an environment where teams can share insights and expertise seamlessly. This collaboration enhances both speed and accuracy in decision-making.
• Optimizing Knowledge Networks: KMOs establish and maintain networks that allow for the efficient transfer of information. These networks are not just technological but also human, relying on relationships and trust to function effectively.
• Monitoring and Evaluating KM Systems: Continuous improvement is key. KMOs regularly assess the effectiveness of knowledge management systems, using metrics and feedback to refine processes and ensure they meet evolving operational needs.
• Integrating Knowledge into Operations: Perhaps the most critical responsibility, KMOs ensure that knowledge is not just stored but actively used. They embed knowledge-sharing practices into daily operations, ensuring that every decision is informed by the best available information.

In fulfilling these responsibilities, KMOs serve as the Army’s knowledge architects, ensuring that information is not just a resource but a strategic advantage. Their work underpins the Army’s ability to adapt, innovate, and excel in an unpredictable world.

Pros and Cons of Knowledge Management Officers in the Army

Integrating Knowledge for Strategic Decision-Making: The KMO's Role

Strategic decision-making in the Army is a high-stakes process where the margin for error is razor-thin. This is where the Knowledge Management Officer (KMO) steps in, playing a critical role in ensuring that decisions are not only informed but also forward-thinking and adaptive. By integrating knowledge into the decision-making framework, KMOs provide leaders with the clarity and context needed to act decisively, even in the face of uncertainty.

The integration of knowledge is not a one-size-fits-all approach. It requires tailoring information to the specific needs of decision-makers while maintaining a balance between speed and accuracy. KMOs achieve this by:

• Streamlining Information Flow: KMOs ensure that relevant data is filtered, organized, and delivered to decision-makers in real time. This prevents information overload and allows leaders to focus on actionable insights.
• Bridging Tactical and Strategic Levels: They act as a conduit between operational units and higher command structures, ensuring that ground-level realities inform strategic planning and vice versa.
• Leveraging Predictive Insights: By analyzing historical data and trends, KMOs help forecast potential scenarios, enabling leaders to anticipate challenges and opportunities before they arise.
• Fostering Shared Understanding: Decisions are most effective when all stakeholders operate from a common knowledge base. KMOs facilitate this by promoting transparency and ensuring that all parties have access to the same critical information.

One of the most challenging aspects of this role is navigating the complexity of modern military operations. Whether it’s coordinating multinational efforts or responding to rapidly changing battlefield conditions, KMOs must ensure that knowledge integration remains seamless. Their ability to synthesize diverse information sources into a coherent narrative often determines the success of strategic initiatives.

Ultimately, the KMO’s role in strategic decision-making is about enabling leaders to make informed, confident choices. By embedding knowledge into every layer of the decision-making process, they transform raw data into a powerful tool for achieving mission objectives.

Developing Effective Knowledge Networks Across Units

In a complex and hierarchical organization like the Army, the seamless exchange of knowledge across units is no small feat. Developing effective knowledge networks is one of the Knowledge Management Officer’s (KMO) most impactful responsibilities. These networks are not just about technology or systems—they are about building connections, trust, and a culture of collaboration that transcends traditional boundaries.

At its core, a knowledge network is a dynamic system that links individuals, teams, and units, enabling them to share insights, experiences, and resources. KMOs take a deliberate approach to designing and maintaining these networks, ensuring they are both robust and adaptable. Here’s how they do it:

• Identifying Key Knowledge Nodes: KMOs pinpoint individuals or teams that hold critical expertise or information. These nodes act as hubs within the network, facilitating the flow of knowledge to where it’s needed most.
• Encouraging Inter-Unit Collaboration: By fostering relationships between units, KMOs break down silos and promote the free exchange of ideas. This often involves creating forums, workshops, or digital platforms where units can interact and share best practices.
• Implementing Feedback Loops: Effective networks rely on continuous improvement. KMOs establish mechanisms for collecting feedback from users, ensuring the network evolves to meet changing operational demands.
• Balancing Formal and Informal Channels: While formal systems like databases and reports are essential, KMOs also recognize the value of informal knowledge-sharing, such as peer-to-peer communication or mentorship programs.

One of the biggest challenges in building these networks is ensuring they remain resilient under pressure. During high-stakes operations, the network must function flawlessly, delivering critical information without delays or bottlenecks. KMOs address this by designing redundancy into the system, ensuring that if one node fails, others can compensate.

Ultimately, effective knowledge networks are about more than just efficiency—they are about empowerment. By connecting individuals and units in meaningful ways, KMOs enable the Army to act as a cohesive, informed, and agile force, ready to tackle any challenge that comes its way.

Education and Training Pathways for Aspiring Knowledge Management Officers

Becoming a Knowledge Management Officer (KMO) in the Army is not a role one simply steps into—it requires a structured and deliberate educational journey. Aspiring KMOs must equip themselves with both theoretical knowledge and practical skills to navigate the complexities of military knowledge management. The Army provides a range of training pathways designed to prepare individuals for this critical role, blending foundational learning with advanced specialization.

Key education and training opportunities include:

• KM Overview Course: This self-paced introductory course serves as the first step for those new to knowledge management. It provides a broad understanding of KM principles, focusing on the importance of knowledge sharing and its impact on organizational success.
• Army Knowledge Management Basics Course: A more immersive program, this 3–5 day course combines theory with hands-on exercises. Participants learn how to apply KM concepts in real-world scenarios, from creating workflows to facilitating collaboration within units.
• KM Qualification Course (KMQC): This advanced course is tailored for those aiming to take on leadership roles in KM. It delves deeper into organizational strategy, KM frameworks, and the integration of knowledge into decision-making processes. Graduates of this course are well-prepared to step into the role of a KMO.
• KM Electives: For those seeking to expand their expertise, elective courses offer specialized training in areas such as digital tools, data analytics, or the management of tacit knowledge. These electives allow individuals to tailor their learning to specific operational needs.
• University Programs: Some aspiring KMOs pursue formal academic qualifications in knowledge management or related fields. Degrees or certifications in areas like information systems, organizational leadership, or data science can provide a strong foundation for a career in KM.

What sets these pathways apart is their emphasis on practical application. The Army understands that knowledge management is not just a theoretical discipline—it’s a hands-on role that requires adaptability and problem-solving. Training programs are designed to simulate real-world challenges, ensuring that KMOs are ready to tackle the unpredictable nature of military operations.

For those committed to the journey, the rewards are significant. The education and training pathways not only prepare individuals for the technical aspects of the role but also instill the leadership qualities needed to drive change and innovation within the Army. Aspiring KMOs emerge from these programs as confident, capable professionals ready to lead the charge in transforming knowledge into a strategic asset.

The Career Lifecycle of a Knowledge Management Professional in the Army

The career lifecycle of a Knowledge Management (KM) professional in the Army is a structured yet dynamic journey, offering opportunities for growth, specialization, and leadership. From entry-level roles to senior positions, each stage of the career path builds on the skills and experiences gained in the previous one, ensuring a steady progression toward becoming a strategic leader in knowledge management.

The typical career stages for a KM professional include:

• KM Representative: This is often the starting point for individuals entering the field. At this stage, professionals are introduced to the fundamentals of KM, assisting in implementing knowledge-sharing practices and supporting unit-level initiatives. It’s a hands-on role that focuses on learning the basics of collaboration and data organization.
• KM Specialist: With experience, professionals move into more specialized roles. KM Specialists focus on applying advanced techniques to manage explicit and tacit knowledge effectively. They may lead specific projects, such as designing knowledge repositories or optimizing workflows, while also mentoring junior team members.
• Knowledge Management Officer (KMO): At this level, individuals take on leadership responsibilities, overseeing KM activities across multiple units or even entire commands. KMOs are strategic thinkers, integrating knowledge into operational planning and ensuring alignment with organizational goals. They are also key advisors to senior leaders, providing insights that drive mission success.
• Chief Knowledge Officer (CKO): The pinnacle of a KM career, the CKO role involves shaping the Army’s overall knowledge management strategy. CKOs are visionaries, responsible for fostering a culture of learning and innovation while ensuring that KM practices evolve to meet future challenges. They work closely with top leadership to embed KM into the Army’s long-term objectives.

Throughout this lifecycle, professionals are encouraged to pursue continuous learning and professional development. Whether through advanced training courses, mentorship programs, or participation in cross-functional teams, KM professionals are constantly refining their skills and expanding their expertise.

What makes this career path particularly rewarding is its impact. At every stage, KM professionals contribute to the Army’s operational effectiveness, ensuring that knowledge is not just managed but leveraged as a powerful tool for success. From the first steps as a KM Representative to the strategic oversight of a CKO, each role offers a unique opportunity to shape the way the Army operates and adapts in an ever-changing world.

Knowledge Management Tools and Technologies Used by KMOs

Knowledge Management Officers (KMOs) rely on a variety of tools and technologies to streamline the collection, organization, and dissemination of information across the Army. These tools are designed to enhance collaboration, improve accessibility, and ensure that critical knowledge is available when and where it’s needed. By leveraging these technologies, KMOs transform raw data into actionable insights, enabling informed decision-making at all levels.

Key tools and technologies commonly used by KMOs include:

• Centralized Knowledge Repositories: Platforms such as SharePoint or other military-specific systems act as centralized hubs for storing and organizing explicit knowledge. These repositories ensure that documents, reports, and operational guidelines are easily accessible to authorized personnel.
• Collaboration Tools: Tools like Microsoft Teams or Army-specific communication platforms facilitate real-time collaboration between units. These technologies allow KMOs to bridge geographical distances, enabling seamless knowledge sharing during operations.
• Data Analytics Software: Advanced analytics tools help KMOs process large volumes of data, identifying patterns and trends that can inform strategic decisions. These tools are particularly useful for predictive analysis and operational planning.
• Content Management Systems (CMS): KMOs use CMS platforms to manage the lifecycle of digital content, ensuring that information is up-to-date, relevant, and aligned with operational needs.
• Knowledge Mapping Tools: These tools help visualize the flow of knowledge within the organization, identifying gaps or bottlenecks in information sharing. By mapping out knowledge networks, KMOs can optimize the efficiency of these systems.
• Artificial Intelligence (AI) and Machine Learning (ML): Emerging technologies like AI and ML are increasingly being integrated into KM practices. These tools can automate repetitive tasks, enhance data analysis, and even provide recommendations based on historical knowledge.
• Secure Communication Systems: Given the sensitive nature of military operations, KMOs rely on encrypted communication tools to ensure that knowledge is shared securely and without risk of compromise.

These tools are not static; they evolve alongside the Army’s needs and technological advancements. KMOs must stay ahead of the curve, continuously exploring new technologies and integrating them into their workflows. However, the effectiveness of these tools ultimately depends on how they are used. A skilled KMO knows that technology is only as powerful as the strategies and processes behind it, ensuring that these systems serve the broader mission objectives.

Tacit, Explicit, and Implicit Knowledge: Managing Crucial Information Types

Managing knowledge in the Army is not just about collecting data; it’s about understanding the nature of the information being handled. Knowledge can be broadly categorized into three types: tacit, explicit, and implicit. Each type presents unique challenges and opportunities, requiring Knowledge Management Officers (KMOs) to adopt tailored strategies for effective management.

Tacit Knowledge: This is the hardest type of knowledge to capture and share. Tacit knowledge resides in the minds of individuals and is often based on personal experience, intuition, or skills. For example, a seasoned commander’s ability to make split-second decisions in combat is rooted in tacit knowledge. KMOs work to surface this type of knowledge through mentoring programs, after-action reviews, and fostering environments where experiences can be shared informally.

Explicit Knowledge: Unlike tacit knowledge, explicit knowledge is codified and easily transferable. It includes manuals, standard operating procedures (SOPs), training materials, and reports. KMOs ensure that explicit knowledge is well-organized, stored in accessible repositories, and regularly updated to reflect current practices. The challenge here lies in preventing information overload and ensuring that users can quickly locate what they need.

Implicit Knowledge: Often overlooked, implicit knowledge sits between tacit and explicit knowledge. It refers to knowledge that isn’t formally documented but can be inferred through actions or processes. For instance, a unit’s unspoken understanding of how to adapt to a specific operational challenge is implicit knowledge. KMOs aim to make this knowledge more visible by observing workflows, identifying patterns, and converting them into explicit formats when possible.

Effectively managing these three types of knowledge requires a balanced approach. KMOs must create systems that capture tacit insights without stifling creativity, organize explicit knowledge for easy access, and uncover implicit knowledge to prevent it from being lost. By addressing each type with precision, KMOs ensure that the Army’s collective knowledge remains a powerful asset, ready to be deployed whenever and wherever it’s needed.

Success Stories: Real-World Examples of KMOs in Action

Knowledge Management Officers (KMOs) are often the unsung heroes behind the Army’s operational successes. Their ability to streamline information flow, foster collaboration, and integrate knowledge into decision-making has led to remarkable outcomes in real-world scenarios. Below are some success stories that highlight the transformative impact of KMOs in action.

1. Enhancing Mission Readiness Through Knowledge Sharing

During a large-scale joint training exercise, a KMO identified gaps in communication between participating units. By establishing a centralized knowledge-sharing platform, the KMO ensured that all units had access to updated operational plans, logistics data, and real-time feedback. This initiative reduced redundancy, improved coordination, and significantly increased mission readiness. The exercise concluded with higher efficiency and fewer delays, demonstrating the value of a well-implemented KM strategy.

2. Rapid Adaptation in Disaster Relief Operations

In the aftermath of a natural disaster, a KMO was tasked with coordinating relief efforts across multiple agencies and Army units. By leveraging tacit knowledge from personnel with prior disaster response experience, the KMO created a streamlined process for resource allocation and task prioritization. The integration of explicit knowledge, such as logistical data and procedural guidelines, further accelerated decision-making. The result? Faster deployment of aid and a more effective response to the crisis.

3. Optimizing Knowledge Networks in Combat Zones

In a high-pressure combat environment, a KMO implemented a knowledge network that allowed frontline units to share real-time intelligence with command centers. By using implicit knowledge from soldiers on the ground and combining it with explicit intelligence reports, the KMO enabled commanders to make swift, informed decisions. This network not only improved situational awareness but also reduced the risk of operational errors, ultimately contributing to mission success.

4. Preserving Institutional Knowledge During Leadership Transitions

When a key leader retired from a major Army division, a KMO spearheaded efforts to capture and document their tacit knowledge. Through interviews, after-action reviews, and mentorship programs, the KMO ensured that critical insights were preserved and passed on to the incoming leadership. This proactive approach minimized disruptions and maintained continuity in operations, showcasing the importance of knowledge retention.

These examples underscore the vital role KMOs play in the Army’s success. Whether in training, disaster response, combat, or organizational transitions, their ability to harness and manage knowledge has a tangible impact on outcomes. These stories serve as a testament to the power of effective knowledge management in driving operational excellence.

Challenges and Opportunities in Military Knowledge Management

Military knowledge management (KM) operates in a high-stakes environment where the stakes are often life and death. While the role of Knowledge Management Officers (KMOs) is critical to operational success, it is not without its challenges. At the same time, these challenges present unique opportunities for innovation and growth, pushing the boundaries of what effective KM can achieve in the Army.

Challenges in Military Knowledge Management:

• Data Overload: The sheer volume of information generated during military operations can overwhelm even the most robust KM systems. Filtering relevant data from noise while ensuring no critical detail is overlooked remains a constant struggle.
• Security and Accessibility Balance: Military operations require secure knowledge-sharing systems to protect sensitive information. However, ensuring that these systems are also accessible to authorized personnel in real-time is a delicate balancing act.
• Capturing Tacit Knowledge: Tacit knowledge, often residing in the minds of experienced personnel, is notoriously difficult to document and share. The loss of this knowledge during personnel transitions can create significant gaps.
• Interoperability Across Units: Different units often use varied systems and processes, creating barriers to seamless knowledge sharing. Aligning these systems without disrupting operations is a complex task.
• Resistance to Change: Implementing new KM practices or technologies can face resistance from personnel accustomed to traditional methods. Overcoming this cultural inertia requires persistent effort and strong leadership.

Opportunities for Growth and Innovation:

• Leveraging Emerging Technologies: Tools like artificial intelligence (AI), machine learning (ML), and blockchain offer exciting possibilities for automating data analysis, enhancing security, and improving the accuracy of knowledge systems.
• Building a Knowledge-Sharing Culture: KMOs have the opportunity to foster a culture where knowledge sharing is not just encouraged but becomes second nature. This cultural shift can significantly enhance collaboration and innovation across the Army.
• Cross-Organizational Collaboration: The integration of KM practices across allied forces and civilian agencies can create a unified approach to operations, particularly in joint missions or disaster response scenarios.
• Personalized Learning and Development: By analyzing knowledge gaps within units, KMOs can tailor training programs to address specific needs, ensuring that personnel are better prepared for their roles.
• Resilience in Dynamic Environments: KMOs can design systems that adapt to rapidly changing operational contexts, ensuring that knowledge remains relevant and actionable even in unpredictable situations.

While the challenges in military KM are significant, they are not insurmountable. In fact, they serve as a driving force for innovation, pushing KMOs to develop smarter, more resilient systems. By addressing these obstacles head-on, KMOs not only enhance the Army’s operational capabilities but also pave the way for a future where knowledge truly becomes a strategic asset.

How KMOs Contribute to Mission Readiness and Operational Efficiency

Mission readiness and operational efficiency are two pillars of success in military operations, and Knowledge Management Officers (KMOs) play a pivotal role in strengthening both. By ensuring that the right knowledge reaches the right people at the right time, KMOs enable units to act decisively and effectively, even in the most challenging environments. Their contributions are deeply embedded in the Army’s ability to adapt, innovate, and execute with precision.

Enhancing Mission Readiness:

• Streamlining Pre-Mission Preparation: KMOs ensure that units have access to updated training materials, intelligence reports, and operational guidelines. This reduces the time spent searching for information and allows personnel to focus on honing their skills and strategies.
• Facilitating Knowledge Continuity: By capturing and transferring critical knowledge during personnel transitions, KMOs prevent disruptions in mission planning and execution. This ensures that new team members can quickly adapt and contribute effectively.
• Identifying Knowledge Gaps: KMOs analyze existing knowledge systems to identify areas where additional training or resources are needed. Addressing these gaps enhances the overall preparedness of units, reducing vulnerabilities during operations.

Driving Operational Efficiency:

• Reducing Redundancy: KMOs eliminate inefficiencies by centralizing knowledge repositories and streamlining workflows. This prevents duplication of effort and ensures that all units operate from a unified knowledge base.
• Optimizing Decision-Making: By providing leaders with actionable insights derived from both explicit and tacit knowledge, KMOs enable faster and more informed decisions. This agility is crucial in dynamic operational environments.
• Promoting Real-Time Collaboration: KMOs facilitate seamless communication between units, ensuring that knowledge flows without delays. This is particularly vital during joint operations or time-sensitive missions.

One of the most significant ways KMOs contribute to mission readiness and efficiency is by fostering a culture of proactive knowledge sharing. They don’t just manage information—they create systems and practices that empower personnel to learn from one another, adapt to new challenges, and continuously improve. This holistic approach ensures that the Army remains not only prepared for current missions but also resilient in the face of future uncertainties.

Future Trends in Knowledge Management for the Army

The future of knowledge management (KM) in the Army is poised to be shaped by emerging technologies, evolving operational demands, and a growing emphasis on agility and innovation. As the nature of warfare and military operations continues to change, Knowledge Management Officers (KMOs) will need to adapt their strategies to harness new tools and methodologies. Here’s a glimpse into the trends that are likely to define the next era of KM in the Army.

1. Integration of Artificial Intelligence (AI) and Machine Learning (ML)

AI and ML are set to revolutionize how knowledge is processed and utilized. These technologies can automate data analysis, identify patterns in vast datasets, and even predict future scenarios based on historical trends. For KMOs, this means faster access to actionable insights and the ability to anticipate challenges before they arise. AI-driven systems will also enhance decision-making by providing leaders with real-time recommendations tailored to specific operational contexts.

2. Advanced Knowledge Visualization

As data becomes more complex, visualizing knowledge effectively will be critical. Future KM tools are likely to incorporate advanced visualization techniques, such as interactive dashboards and 3D mapping, to help personnel understand relationships, trends, and gaps within their knowledge networks. These tools will make it easier to translate raw data into meaningful, strategic insights.

3. Decentralized Knowledge Systems

With the rise of blockchain technology, decentralized knowledge systems may become a reality. These systems will enhance security, ensure data integrity, and allow for more efficient sharing of information across units and allied forces. KMOs will play a key role in implementing and managing these decentralized networks, ensuring that they align with operational needs.

4. Focus on Real-Time Knowledge Sharing

Future operations will demand even faster knowledge exchange. KMOs will need to leverage technologies that enable real-time sharing of tacit, explicit, and implicit knowledge, ensuring that personnel on the ground and in command centers are always on the same page. This could include augmented reality (AR) tools that provide instant access to critical information during missions.

5. Emphasis on Knowledge as a Strategic Asset

The Army is likely to place an even greater emphasis on treating knowledge as a core strategic resource. KMOs will be tasked with not only managing knowledge but also demonstrating its value in achieving mission objectives. This shift will require KMOs to adopt a more proactive, results-driven approach to their work.

6. Enhanced Collaboration Across Allied Forces

As multinational operations become more common, KMOs will need to facilitate knowledge sharing across diverse organizations and cultures. Future KM systems will need to support interoperability, ensuring that allied forces can collaborate seamlessly while maintaining security and operational efficiency.

The future of KM in the Army is both exciting and challenging. By staying ahead of these trends, KMOs will continue to play a vital role in ensuring that the Army remains agile, informed, and prepared for whatever lies ahead. As technology evolves and operations grow more complex, the importance of effective knowledge management will only continue to grow.

Conclusion: Knowledge as a Strategic Asset for Modern Military Operations

In modern military operations, knowledge is no longer just a supporting element—it has become a strategic asset that can determine the success or failure of missions. The role of Knowledge Management Officers (KMOs) is central to this transformation, as they ensure that information is not only collected but also effectively utilized to drive decisions, foster collaboration, and enhance operational readiness.

By integrating advanced tools, fostering a culture of knowledge sharing, and bridging gaps between units, KMOs have redefined how the Army approaches its most critical challenges. Their work goes beyond managing data; it is about creating systems that empower personnel, reduce inefficiencies, and enable rapid adaptation in dynamic environments.

Looking ahead, the importance of knowledge management will only grow as operations become more complex and technology continues to evolve. KMOs will remain at the forefront of this evolution, leveraging innovations like artificial intelligence, decentralized systems, and real-time collaboration tools to ensure that the Army remains agile and informed.

Ultimately, knowledge is the Army’s invisible force multiplier. It strengthens decision-making, enhances coordination, and builds resilience in the face of uncertainty. Through the tireless efforts of KMOs, knowledge is transformed from a static resource into a dynamic advantage, ensuring that the Army is always prepared to meet the demands of modern warfare.

FAQ: Knowledge Management in the Army