Analysis / Forces

Rebuilding Military Forces: Needed, But In Phases

Transition45 Series

Photo courtesy of US Navy:

During the campaign, President–elect Trump laid out his vision for military forces: a regular Army of 540,000 soldiers, a Navy of 350 ships, an Air Force of 1,200 fighter attack aircraft, a Marine Corps of 36 active-duty infantry battalions, plus increased missile defense and cyber capabilities. (For additional detail on the president-elect’s proposal, see my analysis here. For a discussion of the status and issues regarding U.S. military forces, see my monograph U.S. Military Forces in the FY 2017 Budget).

There is broad agreement in the national security community that additional forces are needed to meet the demand of on-going conflicts, crisis response, and wartime surge. The new administration should therefore begin some force expansion immediately. However, it should implement the force expansion in two phases to ensure that it is fully executable and consistent with the administration’s national security and fiscal strategies.


Bottom Line

The administration is right to rebuild military forces. However, it should not put out a hasty plan that it later has to walk back in future budgets as strategic needs and fiscal constraints become clearer.

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All the military services have real shortfalls compared with what they are being asked to do. However, each of the services is in a different position.


In 2001, the total Army (regulars, Guard, and reserve) had 1,039,000 soldiers; the Obama administration’s “postwar” target is 980,000. So the Army would be 59,000 soldiers smaller coming out of the wars in Iraq and Afghanistan than going into them. However, it is not clear that the world will put fewer demands on the Army.

The recently-passed FY 2017 National Defense Authorization Act (NDAA) stopped the planned reduction of the active force to 450,000 and, instead, increased it to 480,000. Similarly, the Army’s Guard and reserve components will be increased instead of cut. The total Army will be 1,035,000, about its size in 2001. The additional personnel would fill gaps and shortfalls, thus increasing readiness.

FY 2017 NDAA


The recently-passed FY 2017 National Defense Authorization Act (NDAA) stopped the planned reduction of the active force to 450,000 and, instead, increased it to 480,000.

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The first inclination in adding further personnel will be to build additional brigade combat teams because these constitute highly visible combat power. The Army does need some additional combat power both for day-to-day operations and wartime surge. But the Army needs other capabilities as well. For example, the National Commission on the Future of the Army proposed building short range air defense units. These were greatly reduced and put into the reserves at the end of the Cold War when adversary aviation threats declined. Now there are threats from UAVs, cruise missiles, and tactical aircraft. Many analysts have proposed increasing missile defense capabilities. Yet others have proposed new kinds of capabilities such as anti-ship missiles and counter-mortar/artillery.

Further, the Heritage Foundation force structure that Trump cited was entirely active-duty and does not include any reserve component expansion. The new administration might want to expand the reserves to broaden recruiting, ease fiscal demands, and acknowledge the role (and political power) of the reserve components.


Navy force size is a good news/bad news story. The good news is that, despite the fleet’s small size of 275 ships today, ships already funded will increase fleet size when delivered, reaching the target of 308 ships in 2021. The bad news is that the Navy is only meeting about half the regional commanders’ (unconstrained) requests. Further, the Chinese navy continues to grow in size and capability, and the Russians are going to sea again after a two-decade interlude. As a result, the Navy has conducted and will soon release a new force structure assessment. The expectation is that the new requirement will be higher than 308 ships.

If the Trump administration wants to increase ship count, it will need to build existing types of ships with proven designs but in greater numbers. That means buying additional DDG-51 class destroyers, Virginia class submarines, LPD/LSD amphibious ships and auxiliaries like the T-AKEs and ESD/ESBs (renamed from the original MLP/AFSBs). It should not make the mistake that the Bush administration did of putting large amounts of time and money into developing new types of ships and then being unable to produce them in quantity (for example, the DDG-1000). Beyond these ship classes, there are some difficult choices and many different ways to get to 350 ships. It’s worth taking some time to make decisions.

For example, the new administration will want to see how the follow-on to the disappointing LCS-class comes out. If this new ship class is successful, then the administration might want to buy relatively large numbers to cover the many maritime requirements―such as escorting merchant ships and Navy auxiliaries in wartime and engaging allies and partners in peacetime―that don’t require high-end capabilities. It will also want to think hard about the number of Navy carriers. It will likely continue to build the Ford class as planned, but any acceleration would be very expensive, take a long time, and, in the estimation of many naval analysts, divert funds from more survivable platforms. It doesn’t want to get into a situation where it builds new carriers but retires existing carriers early to save money (as nearly happened in 2014).

Air Force

Like the other services, the Air Force notes how busy it is and how this exceeds what was expected—1.7 million hours of flying, 20,000 airmen deployed overseas. This is driven by the ongoing air wars in Afghanistan and Syria/Iraq, responding to tensions in the western Pacific, and increased activity in Europe in response to Russian aggression. The NDAA added 4,000 personnel to support the growing fleet of F-35s while maintaining the A-10 fleet, which the Air Force had proposed retiring but which the Congress insisted on retaining.

In designing its forces, the Air Force faces several tough tradeoffs:

  • Stealth v. non-stealth. Stealth is helpful in high threat environments, but it comes at a high fiscal and performance cost.
  • Manned v. unmanned. Manned aircraft can still do some things that unmanned aircraft cannot, but the gap is narrowing.
  • Fighters v. bombers. The Air Force has launched a major new bomber program, the B-21, that competes with fighter/attack aircraft for money and at least some missions.

One obstacle in getting to the goal of 1,200 fighters is Trump’s stated reservations about the F–35 aircraft. He will be reluctant to increase production without being assured that the aircraft is meeting its performance and cost targets.

Photo courtesy of US Air Force:

The high cost and resulting low procurement numbers of the F-35 will likely drive the Air Force to a high/low mix in the future, as candidate Trump seemed to support. In this case, the Air Force will need to continue upgrading its legacy aircraft. If the department can convince the new administration that the F-35 has overcome its development problems, then production rates might be increased, although the cost–quantity trade-offs will still need to be resolved. Like the Army, the Air Force may want to put some of the force structure expansion into the reserve component.

Marine Corps

Of all the services, the Marine Corps is probably the most stressed by its operational tempo. Ideally, units would have three periods of time at home for every period deployed. However, currently they have only two, and less in some communities. So some expansion is needed. The NDAA adds 3,000 marines, for a total end strength of 185,000. However, building the Marine Corps to 36 infantry battalions, as Trump proposed, would expand the Corps to about 240,000, including the aviation, combat support, and logistics units that, by Marine Corps doctrine, support the infantry. The Marine Corps has not been that large since the height of the Vietnam War. Whether the Marine Corps could attain this size is open to question. Estimates that such an expansion would take only an additional 12,000 marines ignore the support that these additional units need. In addition, the Commandant, General Neller, has stated his desire to build, or expand, capabilities like cyber, intelligence, and electronic warfare, not just infantry.

Other force demands.

The president-elect proposed expanding missile defense and cyber but without detail. He did not mention special operations forces, which might also expand given their high operational usage.

Recommended Changes

Phase 1: Stop planned personnel reductions and procure additional equipment. The first phase should build on the NDAA additions to plug highest priority gaps and procure additional equipment from existing production lines. This could be executed in the FY 2018 budget that the administration will send to the Congress in the spring of 2017. There is no need to rush and provide a full five-year plan at that time. Other transitions have waited until completion of their strategic review.

Phase 2: Plan the expansion. The force expansion is not clear-cut. First, it must be aligned with a strategy, an unfinished task as noted in an earlier Transition45 paper (Realizing “Peace Through Strength”). Then it must be reconciled with other defense priorities such as rebuilding readiness, increasing modernization, and protecting the all-volunteer force. Finally, there are the practical questions of deciding which forces to build. For example:

  • What kinds of units should the Army build in getting to 540,000 soldiers?
  • What ships would comprise the 350 ship goal?
  • What is the right balance of new, fifth generation aircraft and legacy fourth generation aircraft in the Air Force, and of manned/unmanned platforms?
  • Can the Marine Corps really field 36 active-duty infantry battalions when all the customary support is considered?
  • What additional cyber, missile defense, and special operations capabilities are needed?

Answering these questions will take time and involve a difficult discussion of strategy, risks, and priorities. Some questions may be answered in the administration’s strategic review, due out in February 2018 with the FY 2019 budget, but others may take longer to resolve.

Bottom Line

Answering these questions will take time and involve a difficult discussion of strategy, risks, and priorities.

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It will be tempting for a new team to declare the situation a “disaster” and propose across-the-board increases in force structure and elsewhere. However, the administration should not put out a hasty plan that it later has to walk back in future budgets as strategic needs and fiscal constraints become clearer. That would undermine the credibility of the whole rebuilding effort.

Focus the increases. Whatever it decides to do, the Trump administration should focus its funding increases to accomplish the force expansion that it intends. If it provides budget relief to the defense department as a whole, then the bureaucracy will allocate the money to the many claimants in the services and agencies. Every activity—from procurement, to readiness, to base operations, to logistics, to headquarters—will get its “fair” share. While this will ease the stress on many elements of the department, it will dissipate the impact of the additional resources, reduce incentives to find efficiencies, and, in the end, not produce the kind of changes that the Trump administration has publicly committed to.

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