[GlobalSecurity.org]

As the U.S. national security establishment grapples with the implications of the changing character of warfare in the early 21st century, one of more difficult questions to be addressed will be how to properly structure its land combat forces. After nearly two decades of irregular warfare, advocates argue that U.S land forces are in need of recapitalization and modernization. Their major weapons systems are aging and the most recent initiative to replace them was cancelled in 2009. While some upgrades have been funded on the margins, U.S. Army and U.S. Marine Corps leaders have also committed to developing a new warfighting doctrine—Multi-Domain Battle (MDB)—to meet the potential challenges of 21st century warfare.

Because conflicts arising from Great Power rivalries and emerging regional challenges pose the greatest potential strategic danger to the U.S., some have called for optimizing the Army to execute combined arms maneuver warfare against peer or near-peer armies. Recent experience suggests however that the most likely future conflicts the U.S. will engage in will involve ongoing post-Cold War ethnic and nationalist-driven political violence, leading others to support a balanced force structure also capable of conducting wide-area security, or stabilization operations and counterinsurgency.

The Army attempted in 2011 to define wide-area security and combined arms maneuver as the two core competencies in its basic doctrine that would allow it to best prepare for these contingencies. By 2016, Army doctrine abandoned specific competencies in favor of the ability to execute “unified land operations,” broadly defined as “simultaneous offensive, defensive, and stability or defense support of civil authorities tasks to seize, retain, and exploit the initiative and consolidate gains to prevent conflict, shape the operational environment, and win our Nation’s wars as part of unified action.”

The failure to prioritize strategic missions or adequately fund modernization leaves the Army in the position of having to be ready to face all possible contingencies. Gates Brown claims this is inflicting an identity crisis on the Army that jeopardizes its combat effectiveness.

[B]y training forces for all types of wars it ends up lessening combat effectiveness across the entire spectrum. Instead of preparing inadequately for every war, the Army needs to focus on a specific skill set and hone it to a sharp edge… [A] well-defined Army can scramble to remedy known deficiencies in combat operations; however, consciously choosing not to set a deliberate course will not serve the Army well.

The Army’s Identity Crisis

To this point, the Army has relied on a balanced mix of land combat forces divided between armor (heavy tracked and medium wheeled) and light infantry formations. Although optimized for neither combined arms maneuver nor wide-area security, these general purpose forces have heretofore demonstrated the capability to execute both missions tolerably well. The Active Army currently fields 10 divisions comprising 31 Brigade Combat Teams (BCTs) almost evenly split between armor/mechanized and infantry (16 armored/Stryker and 15 infantry).

Major Nathan Jennings contends that the Army force structure should be specifically reorganized for combined arms maneuver and MDB.

Designed to maximize diverse elements of joint, interorganizational and multinational power to create temporary windows of advantage against complex enemy systems, the Army’s incorporation of the idea should be accompanied by optimization of its order of battle to excel against integrated fire and maneuver networks. To that end, it should functionalize its tactical forces to fight as penetration, exploitation and stabilization divisions with corresponding expertise in enabling the vast panoply of American and allied coercive abilities.

This forcewide realignment would enable “flexible and resilient ground formations [to] project combat power from land into other domains to enable joint force freedom of action,” as required by Gen. David G. Perkins, commander of the U.S. Army Training and Doctrine Command. While tailored brigades and battalions would feature combined arms with the ability to maneuver in a dispersed manner, optimized divisions would allow functional expertise in rear, close, deep and non-linear contests while maintaining operational tempo throughout rapid deep attacks, decisive assaults, and consolidation of gains. The new order would also bridge tactical and operational divides to allow greater cross-domain integration across the full range of military operations.

On the other hand, Lieutenant Colonel Jason Nicholson advocates heeding the lessons of the last decade and a half of U.S. experience with irregular warfare and fielding an upgraded, yet balanced, force structure. He does not offer a prescription for a proper force mix, but sees the recent Army decision to stand up six Security Force Assistance Brigades (SFABs) as an encouraging development.

The last sixteen years of ongoing military operations have been conducted at the expense of future requirements of all types. The modernization problems presented by “small wars” challenge the Army as surely as those related to high-intensity conflicts. While SFABs are a step in the right direction, greater investment is required to maximize the lessons learned after sixteen years of counterinsurgency. Training for specific missions like combat advising and security force assistance should be institutionalized for tactical units beyond the designated SFABs. The need for additional capabilities for operating in austere environments will also drive equipment requirements such as lighter power generation and enhanced tactical mobility. Greater expeditionary logistics, armor, and fire support assets will also be critical in future operations. Hybrid warfare, from the Russian campaign in Ukraine to the French campaign in Mali, will continue to change the nature of “small wars.” Megacities, climate change, and other similar challenges will require the same attention to detail by the Army as near-peer conflict in order to ensure future operational success.

No Simple Answers To Strategic Insolvency

Decisions regarding the Army’s force structure will be in the hands of senior political and military decision-makers and will require hard choices and accepting risks. Proponents of optimizing for combined arms maneuver concede that future U.S. commitments to counterinsurgency or large-scale stabilization operations would likely have to be curtailed. Conversely, a balanced force structure is a gamble that either conventional war is unlikely to occur or that general purpose forces are still effective enough to prevail in an emergency.

Hal Brands and Eric Edelman argue that the U.S. currently faces a crisis of “strategic insolvency” due to the misalignment of military capabilities with geopolitical ends in foreign policy, caused by the growth in strategic and geopolitical challenges combined with a “disinvestment” in defense resources. They contend that Great Powers have traditionally restored strategic solvency in three ways:

• “First, they can decrease commitments thereby restoring equilibrium with diminished resources.”
• “Second, they can live with greater risk by gambling that their enemies will not test vulnerable commitments or by employing riskier approaches—such as nuclear escalation—to sustain commitments on the cheap.”
• “Third, they can expand capabilities, thereby restoring strategic solvency.”

Brands and Edelman contend that most commentators favor decreasing foreign policy commitments. Thus far, the U.S. has seemingly adopted the second option–living with greater risk—by default, simply by avoiding choosing to reduce foreign policy commitments or to boost defense spending.

The administration of President Donald Trump is discovering, however, that simply choosing one course over another can be politically problematic. On the campaign trail in 2016, Trump called for expanding U.S. military capability, including increasing U.S. Army end strength to 540,000, rebuilding the U.S. Navy to at least 350 vessels, adding 100 fighter and attack aircraft to boost the U.S. Air Force to 1,200 aircraft, and boosting the U.S. Marine Corps from 24 battalions to 36. He signed an executive order after assuming office mandating this expansion, stating that his administration will pursue an as-yet undefined policy of “peace through strength.”

Estimates for the cost of these additional capabilities range from $55-$95 billion in additional annual defense spending. Trump called for an additional $54 billion spending on defense in his FY 2018 budget proposal. Secretary of Defense James Mattis told members of Congress that while the additional spending will help remedy short-term readiness challenges, it is not enough to finance the armed services plans for expansion and modernization. As Congress wrangles over a funding bill, many remain skeptical of increased government spending and it is unclear whether even Trump’s proposed increase will be approved.

Trump also said during the campaign that as president, he would end U.S. efforts at nation-building, focusing instead on “foreign policy realism” dedicated to destroying extremist organizations in conjunction with temporary coalitions of willing allies regardless of ideological or strategic differences. However, Trump has expressed ambivalent positions on intervention in Syria. While he has stated that he would not deploy large numbers of U.S. troops there, he also suggested that the U.S. could establish “safe zones” His cabinet has reportedly debated plans to deploy up to tens of thousands of ground troops in Syria in order to clear the Islamic State out, protect local populations, and encourage the return of refugees.

It does not appear as if the Army’s identity crisis will be resolved any time soon. If the past is any indication, the U.S. will continue to “muddle through” on its foreign policy, despite the risks.