I'm certainly no foreign policy expert, but frankly I’ll be surprised if Vladimir Putin does decide to invade because there appears to be very little upside to it.
If he invades, his military will suffer horrendous losses against a well-armed, well-trained Ukrainian military fighting on its home turf, the economic cost of war would be high and the economic sanctions the West could impose would be catastrophic to the Russian economy.
Moreover, although experts expect the Russian military to ultimately prevail, once they capture the country they'd have to hold it against an insurgency comprised of a Ukrainian citizenry which is itself heavily armed. As more troops come home maimed or dead from IEDs, snipers and ambushes, domestic pressure will grow for Putin to get out.
It seems more likely that, rather than suffer these calamities, Putin will resort instead to destabilization efforts like cyber attacks to shut down the Ukrainian banking, health care, transportation and communications systems which, if successful, would throw the country into chaos and precipitate some sort of surrender.
In any case, we’ll probably know what the Russians are going to do soon after the Winter Olympics in Beijing conclude next month.
Meanwhile, someone who is a foreign policy expert, Stephen M. Walt, has a very insightful column at Foreign Policy in which he explains the history behind the current crisis in Ukraine.
According to Walt, the present tinderbox has resulted from both a deeply flawed American policy as well as Putin's own behavior. The U.S. made several mistakes over the last several decades, chief among which was a failure to accept that Russia regards an ever-expanding NATO with the same alarm that the U.S. would regard, and has regarded, Russian expansion into the western hemisphere.
Walt explains:
Although Moscow had little choice but to acquiesce to the admission of Poland, Hungary, and the Czech Republic into NATO, Russian concerns grew as enlargement continued. It didn’t help that enlargement was at odds with U.S. Secretary of State James Baker’s verbal assurance to Soviet leader Mikhail Gorbachev in February 1990 that if Germany were allowed to reunify within NATO then the alliance would not move “one inch eastward” — a pledge Gorbachev foolishly failed to codify in writing.There's more on how the U.S. might've done things differently in Walt's article, but as maladroit as our policy regarding NATO's expansion may have been, Putin's was worse:
(Baker and others dispute this characterization, and Baker has denied that he made any formal pledges.)
Russia’s doubts increased when the United States invaded Iraq in 2003 — a decision that showed a certain willful disregard for international law — and even more after the Obama administration exceeded the authority of United Nations Security Council Resolution 1973 and helped oust Libyan leader Muammar al-Qaddafi in 2011.
Russia had abstained on the resolution — which authorized protecting civilians but not regime change — and former U.S. Defense Secretary Robert Gates later commented that “the Russians felt they had been played for suckers.”
Compounding the error is NATO’s repeated insistence that enlargement is an open-ended process and any country meeting the membership criteria is eligible to join .... [O]penly proclaiming an active and unlimited commitment to moving eastward was bound to further heighten Russian fears.
The next misstep was the Bush administration’s decision to nominate Georgia and Ukraine for NATO membership at the 2008 Bucharest Summit. Former U.S. National Security Council official Fiona Hill recently revealed that the U.S. intelligence community opposed this step but then-U.S. President George W. Bush ignored its objections for reasons that have never been fully explained.
...[O]ther NATO members opposed including [Ukraine]. The result was an uneasy, British-brokered compromise where NATO declared that both states would eventually join but did not say when.
As political scientist Samuel Charap correctly stated: “[T]his declaration was the worst of all worlds. It provided no increased security to Ukraine and Georgia, but reinforced Moscow’s view that NATO was set on incorporating them.” No wonder former U.S. ambassador to NATO Ivo Daalder described the 2008 decision as NATO’s “cardinal sin.”
It is commonplace in the West to defend NATO expansion and blame the Ukraine crisis solely on Putin. The Russian leader deserves no sympathy, as his repressive domestic policies, obvious corruption, repeated lying, and murderous campaigns against Russian exiles who pose no danger to his regime make abundantly clear.Walt's essay is very informative and anyone curious as to how the current situation evolved in and around Ukraine would do well to read it.
Russia has also trampled on the 1994 Budapest Memorandum, which provided security assurances to Ukraine in exchange for its relinquishing the nuclear arsenal it inherited from the Soviet Union.
These and other actions have raised legitimate concerns about Russian intentions, and the illegal seizure of Crimea has turned Ukrainian and European opinion sharply against Moscow. If Russia has obvious reasons to worry about NATO enlargement, its neighbors have ample reason to worry about Russia as well.