U.S. President Barack Obama, who began pulling most U.S. troops out of Europe in 2012, is now shoving them back in, along with enough new battle tanks and artillery for another full infantry brigade to directly face Russia in Eastern Europe.

This is serious business.

The new move brings a fourfold increase in U.S. military spending in Europe — the largest increase since the Cold War ended — to backstop this highly mobile armoured force with its massive firepower.

Consider that the roughly 5,000 new soldiers will lift U.S. strength in Europe up to 82,000 in three brigades, all concentrated on bolstering NATO's eastern defences bordering Russia.

"This is a really big deal, and the Russians are going to have a cow," predicted Evelyn Farkas, a former top Pentagon policy official.

It's a pretty safe forecast.

Russia quickly blasted Obama for escalating tensions "without any reason" and endangering stability in Europe, while hinting it would match any new buildup.

"These steps by the U.S. and NATO are destabilizing and detrimental to the European security," the Russian Embassy in Washington charged.  "There should be no doubt that Russia under any circumstances will be able to defend its citizens and national security interests."

'Persistent' presence

The U.S. escalation, announced last week, is meant primarily to strengthen confidence on NATO's eastern flank, but the timing has surprised many observers.

With Russia largely preoccupied with its military offensive in Syria, the confrontation over the Ukraine has seen "a sharp de-escalation of hostilities since August," according to the UN.

Moscow also charges that this move puts the U.S. in breach of the 1997 NATO-Russia agreement that pledges both sides to avoid placing large numbers of troops along borders facing each other — one of the pillars of post-Cold War confidence-building diplomacy.

The NATO reply, which sounds rather like hair splitting, is that this new brigade will move around a lot and so will be a "persistent" but not a "permanent" presence on a border.

Not surprisingly, Moscow's not buying that line.

But Russia is in a weak position to protest against any U.S. destabilizing of European security given its own movement of armoured divisions westward, following the annexation of Crimea and the borderlands confrontation with Ukraine in recent years.

Several objectives

In practical terms, Washington presents the new brigade as part of a continuing response to security fears that grew directly out of Vladimir Putin's bare-knuckle foreign and defence policies.

But the escalation also has several objectives.

First, it's meant to bolster the confidence of those Eastern European states that fear they might face Putin pressure tactics, or worse, in the future. These include NATO's eastern-most members, such as Hungary, Romania and Poland, and, most especially, the militarily weak Baltic states of Lithuania, Latvia and Estonia.

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Familiar adversaries. U.S. Secretary of State John Kerry talks with Russia's Foreign Minister Sergey Lavrov at the Kremlin in December. (Sergei Karpukhin/Associated Press)

Many of these states have been critical of Obama for being naïve about Putin's expansionary intentions and not acting sooner to shore up NATO defences, something the president had hoped to leave to Western European governments.

"They have finally realized that their previously weaker interest in this part of Europe hadn't done them any favours," Polish security expert Lukasz Kiser told the New York Times. "This decision will try to make up for that."

There is also the strategic consideration that U.S. mobile brigades could quickly switch their focus to southern Europe if needed, should new crises flare up there in the wake of Middle East uncertainties. 

The Pentagon, for instance, is deeply concerned these days about the spreading anarchy in Libya, where ISIS is gathering new strength.  

The 'realist' school

As for the current buildup being directed eastward, this may be far less comforting to the "realist" school of Western diplomats who warned years ago that, apart from Poland, expanding NATO to the very borders of Russia would inevitably provoke unnecessary confrontations,

But the U.S. buildup is clearly also meant to deliver a strong message throughout NATO, including one presumes to Canada, that Washington still regards Russia — not ISIS or China — as its most serious security threat.

The move should also reinforce Washington's demands that the rest of NATO do much more to boost defence budgets and help strengthen the alliance's eastern front.

Several NATO partners, including the U.K., France, Germany and Poland, are currently upping their own security efforts.

And those cited as defence-spending laggards (and Canada is near the bottom rank) can expect more arm twisting.

Canada, already struggling to expand its role in the Middle East, will surely be asked to show more effort on the ground in Europe as well.

Election year

The previous Conservative government was working on plans to help staff a NATO headquarters in Poland and possibly add troops to a new NATO rapid reaction force in Eastern Europe.

There's no clear indication yet of the Trudeau government's plans.

Despite this new buildup, the situation is a far cry from the Cold War when millions of heavily armed NATO and Warsaw Pact troops (both backed by battlefield nukes) faced each other across a dangerous East-West chasm.

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This photo from the Russian Defence Ministry official website shows a bomb being released from Russian Su-24M jet fighter over Syria in October, an air campaign that NATO has strongly criticized. (Russian Defence Ministry Press Service/Associated Press)

Still, crises erupt faster these days, and there's much worry that even a localized flare-up in Eastern Europe could escalate within hours into a much broader conflict.

It is a common worry in foreign ministries now that the momentum of global upheaval has outstripped the capacities of diplomacy to react.

There's clearly a profound need to avoid a new crisis in the region. And NATO and Moscow are supposed to reopen talks soon on how to reduce tensions in the months ahead.

No one's very optimistic at this moment, however, given the uncertainty over Putin's intentions and the tumultuous politicking of a U.S. presidential election year.

Still, we'd better hope sound statesmanship has at least some role to play before the escalation of forces takes on a momentum of its own.