Britain will face defense challenges no matter who wins its upcoming election

Defense has become a hot topic in the run-up to the next British general election, which is likely to be held in October. Keir Starmer, leader of the Labour Party, has been at great pains to differentiate himself from his far-left predecessor Jeremy Corbyn, who advocated terminating Britain’s nuclear deterrent. As Starmer asserted when he became party leader, “never again will Labour go into an election again not trusted on national security.”

Starmer has attacked the governing Conservative Party, arguing that Britain’s forces, notably the Army, have shrunk during the 14 years of Tory rule. As John Healey, Labour’s shadow defense secretary, never tires of pointing out, “when Labour was last in Government in 2010, Britain was spending 2.5% of GDP on Defence, the British Army had over 100,000 troops and satisfaction with service life was 60% … the British Army is now the smallest size since Napoleon.” Indeed, measured in real terms, military spending will not have reached 2010 levels even with the series of increases that have taken place since Russia’s invasion of Ukraine.

Since Labour leads the Tories in almost every poll by at least 20 points, Starmer’s ability to turn the party around on defense is certainly welcome. Starmer has promised to restore the defense share of Britain’s GDP from just over 2.2 percent to 2.5 percent, considerably above NATO’s 2 percent goal and well above the actual spending levels of most NATO members. Yet Starmer has not committed himself to an exact timetable for reaching his objective, merely stating that “we want to get to 2.5 percent as soon as resources allow that to happen.”

Moreover, it is not at all clear that Britain can meet all its defense objectives even if it were to achieve its 2.5 percent goal. Labour remains committed to maintaining Britain’s nuclear deterrent, whose modernization will cost somewhere between £30 and 40 billion and whose costs continue to rise. It plans to spend funds for pay increases and programs such as upgrades to Ministry of Defence (MOD) housing to overcome shortfalls in military recruitment and retention. It also faces a severe funding gap in equipment modernization estimated to amount to as much as £30 billion by 2033.

There is a widespread consensus that the MOD’s inefficient acquisition system desperately needs major reform, which the ministry last attempted in 2011. John Healey has quoted the nonpartisan Public Accounts Committee’s description of the system as “broken and repeatedly wasting taxpayers’ money.” Yet overhauling the defense acquisition system has proved as difficult in London as it has been in Washington. Without significant reform, acquisition costs will continue to grow, with the likely result that Labour will be unable to realize its plans for increasing force levels.

Finally, Healey has made it clear that Labour wishes to focus Britain’s defense capabilities on Europe rather than East Asia. Whether that means also backing away from the so-called Pillar One of the AUKUS agreement, which calls for British participation in the plan to provide Australia with nuclear powered submarines, is not at all clear. Certainly, given the priority that Labour is assigning to Britain’s strategic nuclear deterrent, and its need to address the many other defense challenges that it has identified, it might well give short shrift to funding the AUKUS program. It is noteworthy that Labour has actually said little publicly about its future plans for funding its part of the AUKUS submarine plan.

In any event, despite the spending objectives that Labour has already identified, it is not at all clear whether it will find the resources to meet them. Labour has also pledged to reverse years of domestic spending cuts, and to revitalize programs such as the ailing National Health Service. Domestic spending is certain to increase top-line pressures on the defense budget.

It is worth noting that the prospects for significant defense increases would not be much better in the unlikely event that the Tories somehow manage to remain Britain’s governing party. It is true that, for their part, the Conservatives also have promised to reach the 2.5 percent objective and, unlike Labour, have explicitly stated that they intend to reach that goal by 2030. In that regard, Defence Secretary Grant Shapps announced earlier this week that the government would acquire six new warships to bolster the Royal Navy’s shrunken fleet.

Nevertheless, much could happen between now and then to forestall reaching that objective. Indeed, it is exceedingly difficult to meet stated “out year” objectives that extend beyond two or at most three years. Moreover, the Conservatives will face all the defense budgetary challenges that Labour has identified, as well as growing popular pressures for increases in domestic spending.

Regardless of which party forms the next British government, it will find that actually restoring the country’s defense posture will take more than promises made during the election season. In that respect, Britain and America will have much in common. Biden administration forecasts of increases in defense spending after Fiscal Year 2025 that will supposedly alleviate pressure on force levels, and similar promises from the Trump campaign, likewise may prove far more difficult to realize once the next administration takes office on January 20.

Dov S. Zakheim is a senior adviser at the Center for Strategic and International Studies and vice chairman of the board for the Foreign Policy Research Institute. He was undersecretary of Defense (comptroller) and chief financial officer for the Department of Defense from 2001 to 2004 and a deputy undersecretary of Defense from 1985 to 1987.