All quiet on the eastern flank? Not anymore. A nightmare scenario has been playing on eastern European minds with increasing intensity since Donald Trump returned to the White House: what if Russia attacks and the US does not join the fight? On the rare occasions the question is posed out loud, nobody much likes the answer. In mid-May, at a gathering in Tallinn, the US undersecretary of state Thomas DiNanno was asked directly whether American troops would fight if Russia invaded the Baltic states. He shifted uncomfortably in his chair, then gave a meandering answer. It did not include the word “yes”.
Politicians from the region usually try to sidestep the issue in public, claiming Washington’s commitment to Nato allies remains strong, and the alarming rhetoric from the Trump administration should not be taken to heart. “We shouldn’t pour fuel on the fire” is a mantra that was repeated in interviews by ministers from several countries on the eastern flank, where proximity to Russia infuses security debates with extra intensity. Others admit that things are fraught between Europe and the US, but say a break in relations is out of the question, because the security gaps if the Americans absconded would be unbridgeable.
The Growing Fear of US Abandonment
Dovilė Šakalienė, a former Lithuanian defence minister, compared the relationship to “a dysfunctional family where divorce is not an option”. In private, informal conversations are taking place in whispers. What would the response to a Russian attack look like if the US did not show up? Should Europe be doing everything to keep Trump on side – or be drawing up plans for the event that Washington does not come through? And will Vladimir Putin look at the unease in Nato and decide it is the perfect time to test the alliance’s resolve?
This account tracks the discussions in the eastern half of Europe during the 18 months since Trump took office for a second term, and shows how the prevailing mood has morphed from cautious approval of his demands for Europe to spend more into real doubts over US commitment to collective defence. It draws on interviews with dozens of officials in multiple countries, including national leaders, foreign and defence ministers, intelligence bosses and diplomats, many of whom spoke without attribution to discuss one of the most sensitive current foreign policy debates.
Psychological and Geopolitical Dimensions
Ultimately, it is a psychological question as well as a geopolitical one. Eastern Europe has been one of the world’s most pro-American regions since the fall of communism. Poland joined Nato in 1999, the three Baltic states joined in 2004, and US security guarantees have been a fundamental part of national defence strategies ever since. Now, these countries face the possibility they might be abandoned by their primary ally.
One senior official in the region described a sense of bemused disillusionment: “What do you do when your beloved father figure suddenly starts drinking and behaving in a way that is utterly incomprehensible? It’s hard to know how to act.” The first warning shots came in the form of Trump's repeated demands that European Nato members increase their defence spending to 5% of GDP, a target many consider unrealistic. This has fuelled speculation that the US might withdraw from Article 5, the mutual defence clause that is the cornerstone of the alliance.
Key Concerns Among Eastern European Leaders
- Lack of explicit US commitment – No clear assurance that American troops would defend Baltic states in a conflict.
- Potential Russian aggression – Putin may see internal Nato divisions as an opportunity to test the alliance.
- Europe’s defence gaps – Without US support, European militaries lack the capacity to counter a full-scale Russian invasion.
What Europe Can Do Now
European leaders are quietly exploring alternative strategies. Some advocate for increased defence spending and joint EU military procurement to reduce reliance on Washington. Others suggest diplomatic outreach to keep Trump engaged, even if it means accepting his harsh rhetoric. A third camp believes Europe must accelerate its own nuclear deterrent and intelligence-sharing frameworks.
According to a report from the European Council on Foreign Relations, the US contributed roughly 20% of Nato’s total defence spending in 2025, but European allies have been ramping up their budgets. Still, the gap in advanced capabilities—such as air power, missile defence, and cyber warfare—remains significant. A table below summarises the current defence spending of key eastern flank nations:
| Country | Defence Spending (% of GDP) | Nato Target (2%) |
|---|---|---|
| Poland | 4.2% | Met |
| Estonia | 3.4% | Met |
| Latvia | 2.8% | Met |
| Lithuania | 3.1% | Met |
| Romania | 2.5% | Met |
While these numbers show progress, they do not guarantee security. The psychological impact of US ambivalence cannot be overstated. Many eastern Europeans still view America as their ultimate protector, and any sign of wavering could embolden Moscow.
FAQ: Nato’s Eastern Flank and US Support
Q: Could the US really abandon its Nato allies?
A: While a formal withdrawal from Nato is legally complex and unlikely in the short term, the Trump administration has signalled a reduced willingness to intervene. The lack of a clear “yes” from US officials when asked about defending the Baltic states raises serious concerns about the reliability of US commitments.
Q: What would happen if Russia attacked and the US stayed out?
A: Without US military support, European forces would face a formidable challenge. Russia’s conventional military superiority in the region, especially in air power and artillery, could overwhelm local defences. European allies would likely need to rely on rapid reinforcement from other Nato members, but the absence of US logistics and command capabilities would severely limit effectiveness.
Q: How are eastern European countries preparing for this scenario?
A: Nations like Poland and the Baltic states are increasing defence budgets, investing in domestic arms production, and strengthening bilateral defence pacts with other European powers. They are also pushing for a more autonomous EU defence framework, including a joint military command and shared intelligence systems, to reduce dependency on Washington.
