US President Donald Trump's attacks on allies and conciliatory actions toward Russia have made European leaders feel more vulnerable than ever.

US President Donald Trump’s eyebrow-raising visit to Europe has confirmed Europeans’ worst fears: if another “Crimea-like” take-over by Russia occurs somewhere on the continent, they will likely be on their own.

Trump had made it abundantly clear that European leaders can no longer rely on the US for its protection. He was not only harshly criticised by his own party for being too conciliatory with Russian President Vladimir Putin during their Helsinki summit, he also lashed out at US allies once more, going so far as to call the European Union a “foe”.

The US may have more than 60,000 troops stationed in Europe, but a recent report stating the Pentagon is assessing the impact of a possible reduction of troop numbers, coupled with Trump’s unpredictability, has made America’s traditional allies nervous.

Indeed, by initiating trade wars and continuously attacking his closest allies, Trump has weakened the entire West.

Another war in Europe remains possible

Despite his reassurances last week that the US still values NATO, Trump’s divisive visit to Europe may embolden Putin in his assessment that occupying more European land may not be met with much military resistance.

Poland is so concerned, it has recently offered to pay the US up to US$2bn to permanently deploy an armoured division on its soil.

The on-going conflict in Ukraine, coupled with Putin’s increased emphasis in recent years on Russia’s “right” and “obligation” to “protect” ethnic Russians and Russian speakers beyond its borders, contribute further to the unease between Moscow in the West. This is particularly being felt in the Baltic states, two of which (Estonia and Latvia) have sizeable Russian minorities.

It certainly doesn’t help when Russia conducts military drills or dispatches warplanes on the borders with the Baltics, giving a real sense that military escalation in this part of Europe is entirely plausible.

Tensions are building in Eastern Europe

The focus of any possible Russian military incursion could be a thin stretch of land between Poland and Lithuania known as the Suwalki Gap (named after the nearby Polish town of Suwałki), which would allow Russia to reinforce its only access to the Baltic Sea through its Kaliningrad exclave and cut the Baltics off from the rest of Europe.

The Suwalki Gap also links Kaliningrad with Belarus, a staunch Russian ally. Moscow regularly organises joint strategic military exercises with Minsk, the most recent being the Zapad (meaning “West” in Russian) war games last September.

Kaliningrad is strategically important, as well, as the site of recently deployed nuclear-capable short-range missiles and an upgraded nuclear weapons storage site.

Reflecting their concerns about a possible invasion, NATO members held military exercises last June that focused for the first time on defending this 104km strip of land from a possible Russian attack. Then, last month, NATO held the Trojan Footprint 18 joint military exercise in Poland and the Baltics, which was one of its biggest-ever war games in the region.

These military build-ups on NATO’s eastern flank are reminiscent of the Cold War and feed both Russia’s “deep-seated sense of vulnerability vis-à-vis the West” and Europe’s own feelings of insecurity.

Going it alone

But should Russia decide to invade the Suwalki Gap, would Europe go to war over it?

It may not be able to. European military options remain limited as NATO does not have the military means to go to war against Russia without the US. Acutely aware of this, European leaders launched a new regional defence fund last year to develop the continent’s military capabilities outside of NATO.

While a direct Russian invasion of a NATO member would be the worst-case scenario, it’s more likely that Putin would seek to further destabilise the bloc’s eastern flank through a hybrid war involving cyber-attacks, divisive propaganda campaigns and the use of armed proxies like the “little green men” that appeared during the Ukraine conflict.

Even here, though, it’s clear that Europe cannot provide a unified front to counter potential Russian actions. Some countries like Hungary and Italy seek a closer relationship with Russia, while others like the UK are already embroiled in diplomatic conflicts with it.

France and Germany have already announced plans to increase defence spending not because of commitments made to Trump during the latest NATO summit, but out of real concerns that another confrontation with Russia is becoming a real threat.

Trump has weakened the Western alliance at a time when Europe is not ready to step up and ensure its own security. He may have united Europeans around shared fears and their collective response, but he’s also made them more vulnerable.