Update: Trump’s FY18 budget request only calls for $18 billion over Obama’s planned spending levels, a far cry from what is needed to execute his campaign plans.

Note: This article is part of a series exploring Trump’s effect on American defense. For a previous article questioning the efficacy of Trump’s immigration ban, click here.

On November 8, 2016, Donald Trump secured a historic and unexpected victory in the United States presidential election. On the campaign trail, Trump promised to revitalize and expand the US military, which he claims was neglected during the Obama administration. This article will examine his proposals, branch-by-branch.

Before delving into Trump’s military plans, one must consider the limits of executive power. Congress, not the president, passes budgets, so Trump cannot increase military spending unilaterally. However, Trump’s proposals will be viewed favorably by many Republicans in Congress, providing him with an avenue for enacting them. In the past, Obama’s veto was the main obstacle for Republicans who wanted to increase the defense budget. With that roadblock no longer in place, it seems likely that a rise in military spending will occur; the primary Congressional check on Republican power is the Democratic filibuster in the Senate, and the Democrats are usually willing to compromise on defense spending when they get something in return.

The main threat to Trump’s military ambitions will be the expanding federal debt load. If Trump’s promised tax cuts become a reality, federal revenue will be reduced; increasing defense spending in such a fiscal environment would strain the budget and necessitate cuts in other sectors. In the end, the money for a military buildup would probably come at the expense of other federal departments. Even then, a there are a number of fiscal conservatives who must be persuaded that a supplementation of the military budget is necessary.

The Army

Trump’s proposal would enlarge the Army from its current strength of 475,000 active duty soldiers to 540,000. This formidable expansion would allow for the addition of many new combat brigades, increasing the Army’s ability to forward-deploy forces in contested regions, such as Europe and East Asia.

However, such a troop buildup would take many years; expanding the army means not just hiring soldiers but also buying additional helicopters, armored vehicles, and other equipment, all of which take years to contract and deliver. The Army’s new budgetary wish list proposes adding 20,000 troops for 2018, which would bring the force to 490,000. At a rate of 20,000 soldiers per year, it would take over three years to reach 540,000. Whether or not there would be enough willing recruits to fill these additional positions is unclear. During the Global War on Terror, the Army met its recruiting goals by lowering standards. Since Trump’s proposal would have all the military branches searching for recruits simultaneously, such an alteration to standards could again be necessary. The Army is already increasing re-enlistment bonuses in an attempt to retain manpower and grow the force.

In addition to adding soldiers, the Army also highlights the need for upgraded tanks, new electronic warfare capabilities, and additional air defense units. In fact, the replacement of outdated equipment is probably more important than simply adding manpower, as Russia has made great strides in realms such as electronic warfare which the US is looking to counter with its own technologies. Overall, the troop buildup combined with such equipment purchases would add billions to the Army’s budget.

The Marines

Trump’s goal for the Marines is similarly ambitious. It would see Marine Corps strength bolstered to 36 active-duty battalions from its current 26, restoring the Marine Corps’ numbers to Global War on Terror levels. The service would have to recruit the additional Marines while expanding facilities, buying new gear, and dealing with a number of other modernization priorities, similarly to the Army. With all the military branches fighting for new recruits, it may be difficult to find enough manpower to execute the increases. The Marines’ operations are also tied to Navy resources; for example, any new additional expeditionary units would need ships to embark on.

If the expansions are successful, both the Army and the Marines will have to decide how to allocate their new personnel. With the military having largely withdrawn from the ground wars in Iraq and Afghanistan, the need for additional infantrymen is not particularly pressing. Instead, many open positions will be in high-tech fields such as Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR), air defense, maintenance, cyber and electronic warfare, etc. Recruiting star talent in these fields is challenging, but the US military cannot afford to fall behind Russia and China in these areas, and Trump has repeatedly cited improving cyber warfare capabilities as a key goal for his administration. Thus, the military will strive to enhance their hiring efforts in such fields, and may even directly commission cyber experts as officers (this type of recruitment is already in place for other high-skill fields, such as law and medicine).

The Navy

Regarding the Navy, Trump has set an extremely ambitious goal of expanding the fleet to 350 ships from its current strength of around 290 (note that various entities disagree on how to count the Navy’s battle force, and it is unclear what method Trump is using to get his target). While the Army and Marines can be enlarged relatively quickly by purchasing equipment and recruiting more personnel, expanding the Navy is complicated. First of all, the Navy has been severely neglecting maintenance; as of now, almost 2/3 of the Navy’s strike fighters are inoperable due to lack of spare parts or depot backlogs. The surface navy and submarine force are not in much better shape. Fixing these issues is more important to current naval leaders than buying additional equipment.

Furthermore, ships and submarines are capital-intensive assets which take years to deliver after being contracted, and production rate at shipyards is limited. For example, the Virginia-class submarines are to be produced at a steady rate of two per year. To alter this rate would require increasing the workforce significantly and expanding the shipyards’ facilities to handle a 33% increase in workload. Such changes are costly to make and difficult to reverse once undertaken. Undoubtedly, it would be impossible to add 60 ships to the Navy during Trump’s presidency even if he were to win two terms (unless he altered the way ships are counted or purchased a large number of small combat vessels, but neither appears likely). For such a drastic increase in fleet size to take place would require decades of heightened funding and continued support.

Trump’s shipbuilding ambitions could also present a quandary to future administrations. If the current Congress approves funds to expand shipyard production, future governments would inherit said contracts, which they may not be able or willing to execute. For example, if a Democrat or a fiscal conservative were to succeed Trump, they may want to revert shipbuilding to pre-Trump levels to help balance the budget. Terminating contracts, however, would cause massive layoffs of high-paying blue collar naval workers and would nullify the investments made by Trump in upgrading shipyards. Thus, by committing to an aggressive shipbuilding agenda, the current administration could place future governments in an undesirable position.

The Air Force

As for the Air Force, Trump appears to see less of a deficiency. He proposed adding around 100 combat aircraft, which would bring the total to 1,200, a modest increase compared to his plans for the other branches. One interesting question is where these new aircraft would come from. The only multirole fighter currently being purchased by the Air Force is the F-35A, which Trump has expressed disdain for. However, recent price reductions seem to have staved off his attacks, so one can assume an increase in Air Force size would probably come in the form of additional F-35As. Trump had previously proposed competing an improved version of Boeing’s F/A-18E/F Super Hornet against the F-35, but the F/A-18E/F airframe is dated compared to the F-35A and operating a mixed fleet would incur additional maintenance costs in the long run. Plus, the F/A-18E/F was designed to Navy specifications and thus has features which are unnecessary for conventional runway operations.

Some in the military have raised the question of procuring a new attack aircraft to replace or complement the A-10 Warthog, and purchases of such an asset could count towards Trump’s goal of 100 extra aircraft.

UPDATE: As of 3/3/2017, the US Air Force has officially confirmed an industry demo of light attack aircraft. According to acting Air Force secretary Lisa Disbrow, the demo will help the Air Force decide whether or not to go ahead with the light attack program, which aims to quickly purchase a small number of aircraft for counterinsurgency in the Middle East. However, fitting these new aircraft in the Air Force’s stretched budget would certainly be a challenge, regardless of their relatively low price tag.

In conclusion, Trump’s plans are ambitious. They would require the military to expand to wartime personnel levels and rapidly procure new equipment, which experts project would cost from 50 to 90 billion per year. Since Trump has followed through on promises far more controversial than a buildup of the military, it seems almost certain that he still stands behind his original proposal. And because the Democrats have fared poorly in recent elections, the question is not whether the Republicans can legislate Trump’s plan. Rather, they will have to decide whether investing tens of billions in the military is worthwhile, and if so, how to go about it without precipitating a budgetary disaster.