On September 25 while visiting Madrid, British Home Secretary Sajid Javid reiterated that the government is “unconditionally committed” to the security of the continent. At the same time, ministers remain wedded to the vision of “Global Britain,” even after one of its most vocal advocates, Boris Johnson, resigned from government in July. However poorly defined this concept remains, some ministers envisage Britain playing an enhanced role beyond the continent, particularly in the Gulf and the Indo-Pacific. As the former foreign secretary put it in December 2016, “Britain is back East of Suez.”

The trouble is that trade-offs inevitably arise for a state of Britain’s size. Only superpowers can simultaneously play meaningful roles in several regions. The debate between a European and a world role—once dubbed “East of Suez”—is not new. In fact, history suggests that May’s government might wish to reconsider the compatibility of its stated goals.

Just over fifty years ago, a Labour government wrestled with Britain’s external obligations as it tried to reduce defense expenditures, running at just under 6 percent of its gross domestic product in 1964. When Harold Wilson came to power that year, the United Kingdom was shedding its colonial commitments in Africa but retained a substantial presence elsewhere. For instance, this included in the Gulf and in the Far East, where British and Commonwealth forces were defending the newly-federated Malaysia from Indonesian communists. The United Kingdom also had a permanent force of fifty-five thousand troops stationed on the European continent, as part of its treaty obligations to the Western European Union and the North Atlantic Treaty Organization military alliance.

Initially, ministers tried to cancel expensive defense projects while retaining the country’s alliances and obligations. Over the course of two years, fighter jet and bomber programmes were canceled, and a replacement aircraft carrier was also shelved.

Eventually, however, it became clear that these savings would be insufficient, and the government had to scale back its ambitions. Ministers ultimately placed western Europe above the country’s commitments “East of Suez.” Withdrawal planning began in secret after the “confrontation” between Indonesia and Malaysia concluded in August 1966. In July 1967, the announcement was made—to the consternation of the United States, as well as Britain’s allies in the Far East—that Britain would withdraw from the region in the mid-1970s. The drawdown was ultimately accelerated to 1971 by ministers in January 1968, following the devaluation crisis of late 1967. Britain left its staging posts and bases in the Gulf at the same time. The British world role was sacrificed at the altar of the country’s obligations to NATO and European security.

Clearly, historical comparisons are never perfect. The United Kingdom no longer has fifty-five thousand troops stationed on the continent. It was an aspiring member of the European Economic Community in the 1960s, but now it has one foot out the door. Nevertheless, the past does provide some lessons.

Today, the United Kingdom is one of the leading contributors to NATO’s Enhanced Forward Presence in eastern Europe. A contingent of the British Army also looks set to remain in Germany, after the government reversed David Cameron’s decision to withdraw all forces by 2020.

Given these facts, as well as Theresa May’s unconditional commitment to European security, the United Kingdom surely could not afford to send substantial land forces “East of Suez” if tensions threaten to erupt with the Kremlin. And yet, with UK-Russia relations at a new low in the wake of the Salisbury spy poisoning, Britain is sending more troops to assist in Washington’s unwinnable war in Afghanistan.

Given the demands placed on Britain’s overstretched land forces, a planned return “East of Suez” is likely to be primarily a naval enterprise. Indeed, the reopening of a permanent base for the Royal Navy in Bahrain suggests as much. In July, the politically ambitious Defence Secretary Gavin Williamson reiterated his desire to see HMS Queen Elizabeth deployed to the Indo-Pacific in the early 2020s.

Irrespective of Williamson’s aspirations, the United Kingdom is in no position to field a two-fleet navy with Atlantic and Gulf or Indo-Pacific commands. The two aircraft carriers, neither of which can operate simultaneously due to manpower shortages as well as the need for maintenance, will need protection. Given how under-resourced and overstretched the Royal Navy already is, a British maritime task group will likely be heavily reliant on allied support ships. For example, Members of Parliament on the Commons Defence Committee believes that “operating aircraft carriers without the sovereign ability to protect them is complacent at best and potentially dangerous at worst.”

This is a slightly unfair criticism, as the carriers were designed with interoperability in mind, yet it underscores the point that Britain does not have the flexibility that ministers seem to suggest.

Finally, there is the matter of the electorate and how invested they are in these debates. It is hard to see the British people endorsing Theresa May’s “unconditional commitment” to European security in the event of a no-deal Brexit. Furthermore, concerning “Global Britain,” there has been little public debate over the merits and drawbacks of Gavin Williamson’s gunboat diplomacy in the South China Sea. Strategic imperatives may occasionally compel ministers to circumvent the public’s wishes, but a representative government’s foreign policy generally needs popular legitimacy to succeed over the long term.

There are trade-offs in being unconditionally committed to Europe and being a “truly Global Britain.” Together, these roles will lead to dangerous levels of overstretch. Restraint and prioritization should be the watchwords for ministers charting a post–Brexit foreign and defense policy. At a time of extraordinary uncertainty surrounding the U.S. commitment to NATO, can the United Kingdom really afford to devote increasingly sparse resources to regions beyond Europe? Perhaps it is time to revisit the notion of “Global Britain,” now that its foremost champion has returned to the backbenches.

William James (@w_d_james) is a Grand Strategy, Security, and Statecraft Fellow at MIT’s Security Studies Program and Harvard Kennedy School’s Belfer Center for Science and International Affairs.

Image: Britain's Prime Minister Theresa May sits in the audience at the start of the Conservative Party Conference in Birmingham, Britain September 30, 2018. REUTERS/Toby Melville