For much of eastern Europe, Russia is the sleeping beast on the doorstep. But with Donald Trump in the White House, some European nations fear the traditional power structures that kept the beast at bay can no longer be relied upon.
Since its conception in 1949, the North Atlantic Treaty Organisation, or NATO, has been the cornerstone of Europe's security, reports news.com.au.
The treaty binds the United States, Canada, United Kingdom and much of Europe together in a military defence pact, effectively pitting the superior nuclear might of the US against the world's second biggest nuclear power, Russia.
But as the Western alliance shows signs of cracking, some European countries are nervously eyeing Russia and scrambling for a back-up plan.
Poland is so worried that it recently offered the US $2.7 billion to permanently station troops in the country.
Dr Jean Renouf, lecturer in Politics and International Relations at Southern Cross University, said European leaders were growing increasingly fearful of a potential Russian attack on their soil.
"We are currently witnessing an escalation of tensions in the region," he told news.com.au. "It's not that war in Europe is going to happen but we should highlight the fact that another war in Europe could happen if we're not cautious."
Mr Trump's extraordinary performance at the Helsinki summit this week where he met with Russian president Vladimir Putin "underscored the fragility of the Western side," Dr Renouf said.
Parts of the American press labelled Mr Trump's actions at the summit "a betrayal of the country" as he publicly sided with Mr Putin over his own intelligence community. In front of the world, he defended a hostile foreign country while denigrating his own.
During the trip he warned NATO allies that the United States "might go it alone" if they didn't increase defence spending immediately and even referred to the European Union as a "foe".
These often off-script remarks are no doubt music to Mr Putin's ears — a leader who has shown expansionist tendencies.
In 2014, Russia annexed the Crimean Peninsula from Ukraine and since then Mr Putin has placed an increased emphasis on Russia's "right" and "obligation" to protect ethnic Russians and Russian speakers beyond its borders.
Professor Ian Bond, director of Foreign Policy at the Centre for European Reform, agrees with the notion that Mr Trump's fickleness on foreign policy emboldens an expansionist Russia.
"Trump is creating uncertainty about whether the US can be relied upon to defend its allies in a crisis," he told ABC radio on Friday.
"And by creating that doubt that may encourage the Russians to think that some of the states that used to be in its sphere of influence can be dragged back by force or subterfuge."
WAR GAMES AND WEASEL WORDS
The US currently has about 60,000 troops in Europe, many of which are stationed in Germany but recent reports suggest that the Pentagon is reviewing the number of troops on the continent.
"The US government is definitely thinking whether it should reduce its presence in Europe, and this is likely driven by the fact that President Trump is trying to reduce financial commitments in places where he deems them not relevant," Dr Renouf said.
For European leaders, the inconsistent rhetoric and bizarre backflips from President Trump have forced them to ratchet up their defence spending, which is exactly what the US leader wants.
"The unpredictability of President Trump and his lack of clear foreign policy strategy worries the allies further and deepens the sense of urgency that they have to do something and not count on the US should anything happen," Dr Renouf said.
However, what Mr Trump says and what the US does are very different things. In May, the US sent more troops and military to strategic locations in eastern Europe and the Baltics under the banner of Operation Atlantic Resolve. Military officials said the deployment was a large-scale exercise meant to stress logistics skills that would be needed in case of a war on the continent.
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.
For it's part, Russia has conducted its own military drills and dispatched warplanes on the borders of the Baltics states of Estonia and Latvia — both of which have sizeable Russian minorities.
It's this state of affairs that Dr Renouf gives a real sense that military escalation in this part of Europe is entirely plausible. He says with a declining US, European leaders have been aware they need to change their strategic posturing and "that probably happened immediately after the Ukraine war and the annexation of Crimea."
In January, the head of a leading Russian bank has warned of "the growing threat of military conflict" in Europe.
Andrey Kostin, president of VTB, told the UK's Financial Times that his biggest concern was the "dangerous" situation being created by the build-up of arms in Europe.
"We are at the beginning of a new arms race," said Mr Kostin, a close ally of Mr Putin.
"NATO is asking for more weapons and spreading more weapons in Europe and Russia will retaliate absolutely the same."
THE MOST VULNERABLE LAND IN EUROPE
Since coming to office, Mr Trump has consistently chastised the NATO allies over not spending enough on defence and his apparent reluctance to honour parts of the NATO agreement was on display this week when he baulked at the idea of having to defend Montenegro which became a NATO member last year.
It has left some commentators suggesting it puts the US on the path to walking away from the military alliance.
"Qualifying and conditioning the notion of NATO's defence guarantee is a major step on the path to abandoning it," US diplomat and foreign policy expert Philip Gordon wrote in The Atlantic this week.
If military conflict did occur in Europe, it could likely happen along the Suwalki Gap — an area known as "the most vulnerable stretch of land in Europe."
The Suwalki Gap is a thin stretch of land about 104 kilometres long found along the Poland's border with Lithuania.
If Mr Putin was able to seize the land, it 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 and the rest of the Western alliance.
"It's location makes it very strategic. It links the Russian exclave of Kaliningrad with key strategic post for Russia," Dr Renouf said.
"It would be easy to invade if that was the intention … and very difficult to defend."
Last month, US and British aircraft took part in exercises that also involved troops from Poland, Lithuania and Croatia in a simulated defence of the potential flashpoint.
It's highly unlikely the US would abscond from its commitments — Pentagon officials have continually confirmed America's commitment to Europe — but if conflict did break out in eastern Europe and the US chose to stand back and watch it goes without saying that it would be a monumental absence.
"This is very hypothetical but should there be a conflict between Russia and the West, the absence of the US would be significant to the capacity of Europe to respond," Dr Renouf said.
THE NEW AGE OF WARFARE
There are similarities to what Mr Putin has been up to in recent years and China's expansionist moves in the South China Sea.
China's actions have been dubbed the salami slicing strategy in the West for incrementally expanding its position but avoiding any dramatic move that would force the hand of the US.
"There is definitely similarities between Russia and China particularly in the way they have implemented this new, what we call hybrid war or asymmetric war — it's not full fledged confrontation," Dr Renouf said.
"They raise some stakes but not high enough for the West to be justified in responding or intervening with military force."
"The nature of war is changing, so you don't have to have two tanks shooting at each other to call it war. You could very much argue that we're already in the midst of an information war," he said.
"There is so much activity out there that we don't actually notice because no one is dead."