If I had to pick the most important moves of 2014, I would put Russian President Vladimir Putin's flouting of international law and European security norms near the top.
His swift annexation of Crimea -- despite a 1994 treaty signed by Russia and Western allies to guarantee Ukraine's territorial integrity -- as well as his military intervention and support for pro-Russian separatists in eastern Ukraine have destabilized the continent. But Putin's moves on the European chessboard are now checkmating Russia, too.
The year ended with the country in financial chaos, because of Western sanctions over Ukraine, the falling price of oil and Central Bank missteps. The slavish pro-Putin propaganda and the stifling of an independent press had brought nationalist fervor to fever pitch and put the majority of Russians behind him, but when their ruble and their living standards started to collapse by year's end, the grumbling also started.
How much political trouble will this spell for Putin? Will he double down and seek more diversionary foreign (mis)adventures, or will he try to address Russia's isolation, abide by the ceasefire he signed recently for eastern Ukraine, start getting sanctions unraveled and his economy back on track? 2015 is a year to watch for Russia's next moves.
Similarly, Russia could also change tactics and play a constructive role in the horrendous disaster that is Syria. Over nearly four years of war, Russia has given Bashar al-Assad political cover, while Iran has provided most of the Syrian leader's military muscle. More than 200,000 people have now been killed, while the United Nations says there are now more than 3.2 million registered refugees.
And this year, there was the horrible evidence of al-Assad's torture and death squads, as reported on my show. After years of the United States and its allies refusing to intervene in Syria, the big winner of 2014 in that region has been the brutal Islamic State of Iraq and Syria. The rise of ISIS was largely ignored until it swept into Mosul in Iraq and started the gruesome public beadings of journalist colleagues in the summer.
The brutal executions of James Foley, Steven Sotloff and aid workers Alan Henning and Peter Kassig did serve to increase airstrikes and efforts that have somewhat halted the momentum of ISIS. And by the end of 2014, a new government in Iraq, trying to be more inclusive, had taken encouraging first steps.
But the challenge for 2015 remains that few believe ISIS will be stopped, that Iraq will be saved, or that the Syrian war will end until al-Assad leaves power, as President Barack Obama demanded back in 2011.
At the end of yet another year of war there, Valerie Amos, the U.N. under-secretary-general for humanitarian affairs and emergency relief coordinator, told me the lack of a political resolution and the continuing carnage is a stain on the international community.
In his own hemisphere, Obama took bold executive action and formally declared America's isolation of Cuba to be a bankrupt policy that just hasn't worked.
After a half-century of trying to overthrow the Castros with things like the Bay of Pigs fiasco, exploding cigars and even an attempt to infiltrate Cuba's hip-hop scene, Obama threw up America's hands the week before Christmas and announced the United States would be changing tack. It would now engage with Cuba, like allies in Latin America, Canada and Europe.
The President said the two countries would restore diplomatic ties as well as major increases in trade and travel. President Raul Castro, for his part, thanked Pope Francis for his help in pushing the two sides together.
However, 2015 will likely be marked by a furious backlash inside Congress, where Republican opponents can be expected to use their new majority to try to block any new U.S. ambassador to Cuba, refuse funding and especially refuse to lift the embargo.
Yet the question remains how much a new generation of Cuban-Americans will appreciate this? After all, demographics have changed, and they are much more eager to engage than their parents, grandparents and the remaining hard-liners in Congress.
Christiane Amanpour, CNN's chief international correspondent, offers her take on the world's biggest stories in 2014. She is the host of CNN International's nightly global affairs program Amanpour. The views expressed are her own.