Why America keeps pressing its allies and partners to spend more on defence

Since returning to office, US President Donald Trump has appeared relentless in one pursuit: persuading America’s allies to raise defence spending. A key win from his recent NATO summit was what the White House claims as “The Trump Trillion” – a historic US$1.2 trillion (S$1.55 trillion) more in defence spending by NATO since his first term.

The conventional interpretation of such a move is that it enables the US to shoulder less of the burden of safeguarding global security. But Trump’s push goes beyond reducing American commitments and is more accurately about expanding American production through foreign purchases of US weaponry. NATO allies are said to have procured more than US$54 billion in US defence equipment in 2025 alone. 

Foreign policy, in the Trump era, has become industrial policy. Weeks after taking office, he said the US would increase sales to India by “many billions of dollars”. During a trip to Saudi Arabia, he agreed to a US$142 billion arms package, what the White House calls the largest defence deal signed by the US, which would later expand to include 300 American-made tanks and F-35 fighter jets. He has also spent years tying American support for Ukraine to purchases from American companies, conditioning any military support to deals that would flow back on shore. 

As Trump goes around to get countries to increase their spending, his administration is working overtime to find every opportunity for that money to flow back to the US. Trump himself has made this clear, saying at the NATO summit that “we’re sending weapons to NATO, and NATO is paying for those weapons, 100 per cent”. 

The message from the sum of these parts is clear: Defence exports are no longer a by-product of US foreign policy but a core part of the strategy itself. 

Why foreign defence sales are becoming more important

Another way to look at these developments is to acknowledge that Trump is doing what he does best, and here that involves identifying fresh sales opportunities that strengthen the American industrial base, amid a growing global appetite for arms purchases. World military spending reached US$2.887 trillion in 2025, the Stockholm International Peace Research Institute estimates, and defence expenditure grew at 9.2 per cent the same year.

The logic goes beyond Trump’s instinct as a dealmaker. Modern wars have exposed how fragile defence supply chains have become. The conflicts in Ukraine and the Middle East have rapidly depleted stocks of Patriot interceptors, precision-guided munitions and air defence systems, while manufacturers have struggled to replenish inventories fast enough. As the US has discovered in the face of an unrelenting Iran, defence production lines cannot simply be switched on when war begins; they require years of investment, skilled workers and predictable demand. 

But many defence companies slowed down production of missiles and jets as the wars in Iraq and Afghanistan tapered down, with Pentagon budgets shifting to other priorities in other theatres. That came to a head in 2026 in Trump’s war with Iran, which quickly depleted US stores of missiles and interceptors, which will now take three or more years to return to pre-war inventory levels. 

That is where allies come in. Every additional Patriot battery, HIMARS launcher or F-35 ordered abroad helps justify larger production lines, lower unit costs and greater surge capacity for the US itself. 

In just the last 18 months, the Trump administration has announced deals for thousands of new AMRAAMS with Japan, Saudi Arabia and a handful of NATO countries worth billions of dollars. Likewise, HIMARS systems have been sold to Taiwan, Australia and Bahrain, with Taiwan’s purchase of 82 HIMARS launchers and hundreds of rockets estimated at more than US$4 billion. The deals have expanded to maritime systems, with a US$1.7 billion deal with Spain for new AEGIS systems.

In the days leading up to the 2026 NATO summit, the US announced plans to build a Patriot production facility in Europe – the first time that the star of the American arsenal would be built outside the US, requiring European demand to keep that pipeline open. In effect, allies are helping to underwrite America’s defence industrial base long before Washington might need it. 

The domestic element

It is impossible to separate these deals from Trump’s domestic political apparatus. Trump’s singular focus is almost always domestic. He has made a revival of manufacturing a key part of his domestic political agenda, especially in the Midwest, which hosts many defence production lines and was traditionally vote banks for US Democratic supporters. 

That is a move welcomed by the American defence industry, which has spent decades carefully placing factories in a web of places across the US where job losses would be felt most keenly. Pressures from voters to keep jobs there give US officials an incentive to keep factories in their states. 

In my home state of South Carolina, a massive Boeing facility acts as the economic engine for an entire region of the state. If jobs were suddenly cut at the factory, voters would punish anyone tied to that decision. The same is especially true in the Upper Midwest states that have become the critical battlegrounds for the race for the US presidency in the modern age. 

Fresh tensions

A central tension is that this strategy depends on ensuring that higher defence budgets translate into purchases of American equipment rather than European alternatives. That is why the administration has paired calls for greater military spending with an explicit effort to promote US arms exports. Trump himself had signed an executive order on America First Arms Transfer Strategy in February which openly describes foreign purchases as a way of expanding American manufacturing capacity. 

Yet it is doubtful whether this approach will succeed. European governments increasingly worry that dependence on American weapons also means dependence on American politics. Purchasing more US arms goes against the grain of greater independence from a capricious superpower that has seized a Venezuelan leader, threatened to abandon NATO and repeatedly called to take over Greenland.

A platform purchased today locks in decades of maintenance, software updates, spare parts and ammunition, whereas establishing strategic autonomy requires building more of those capabilities at home and reducing dependencies and visible points of vulnerabilities. 

That presents an irony. Trump may well revive America’s defence industry in the short term by persuading allies to buy more American weapons. But by treating defence increasingly as an export business rather than an alliance, he may also encourage those same allies to spend the next decade ensuring they need America less.