2025 began with Donald Trump starting a second term as US President on January 20. All year the US remained the center of global attention, fueled by controversial statements from the US President such as “America must have Greenland.”

Impacts of the United States

President Trump’s return to the White House reshaped international relations throughout 2025, as Washington made sweeping shifts in foreign policy on multiple fronts.

The new US administration changed course on the Russia–Ukraine conflict, resuming dialogue with Moscow and gradually reducing economic and military support for Kyiv to pressure the parties toward a settlement. While no breakthrough has occurred, the approach has reopened diplomatic channels and, crucially, helped avert renewing the spiral of Russia–West confrontation seen in late 2024.

In the Middle East, US engagement helped broker a ceasefire between Israel and Hamas in Gaza, but also complicated the Iran nuclear situation. In late June, the US and Israel took part in strikes against Iranian nuclear facilities, heightening regional tensions. The most far-reaching impact, however, came from a global tariff offensive. President Trump imposed “reciprocal” tariffs on most countries, including allies. The move triggered the world’s largest trade shock in decades, disrupting global supply chains and accelerating the emergence of a more volatile economic order.

Rebecca Lissner, a US foreign policy expert at the Council on Foreign Relations, said: "President Trump's foreign policy in 2025 has been characterized by a year of disruption, and this was evident from the very early days of his presidency when he dismantled the United States' main development agency, USAID. And it carried forward through all manner of policy. We saw April 2nd, so-called Liberation Day, in which the president levied historically high tariffs, not just on US competitors, but also on allies and partners, and inaugurated a roller coaster trade war that continues even to this day."

These shifts were formalized in the new US National Security Strategy released on December 4, signaling a major reordering of Washington’s strategic priorities.

What lies ahead in 2026?

Disputes between the US and Denmark over Greenland, rising US-Venezuela tensions, stalled Russia-Ukraine talks, and retaliatory tariffs between China and the European Union in the final days of 2025 all point to a turbulent start to 2026.

The rapid rollout of the new US security strategy, designating the Western Hemisphere as a non-negotiable US sphere of influence, could turn several regions into new flashpoints next year. Prospects for ending the Russia-Ukraine conflict or advancing phase two of the Gaza peace plan also face major hurdles.

Neil Melvin, Director of International Security at the Royal United Services Institute (RUSI), warned that three dominant trends – rising global instability, deeper divisions and regional conflicts, and a growing risk of direct great-power confrontation – will shape 2026.

Melvin said: "2025 has been a year that's been in many ways defined by increasing security instability and actual conflict. And I think we can see really the, the confluence of three major trends across the year and looking into 2026. One has been this long term trend which has been a move away from the peace and stability that defined the period from the 1980s up until the Arab Spring. So this has been a really sort of global trend. And underpinning this has really been the end of Pax America and the relative decline of the US and the role of the US as a policeman and sort of backing up a whole process of peace, initiatives, mostly through the UN."

Against this backdrop, analysts highlight a potentially pivotal event in early 2026: a planned visit to China by President Trump in the first quarter. The trip could redefine US-China relations and clarify the “G2” framework previously floated by the US president in which Washington and Beijing would set aside strategic differences to jointly manage global affairs, spanning geopolitics, economics, and technology.