Russian President Vladimir Putin's threat to retaliate after what he called Ukrainian "terror" in Crimea — annexed by Russia from its neighbor two years ago — has raised international concerns about the prospect of a return to all-out war. Behind the headlines:
Q: What triggered the latest flare up?
A: Russia says that Ukraine deployed agents to destabilize the Black Sea peninsula and alleges that two of its servicemen were killed in shootouts with them. Ukraine denies the accusations and officials in Kiev have warned that they may be a fabricated pretext for an attack.
Q: What's the situation in eastern Ukraine now?
A: The conflict that erupted in Ukraine's easternmost regions after Russian-backed President Viktor Yanukovych was overthrown in 2014 hasn't gone away. While a peace accord signed in February 2015 stemmed the worst of the fighting, regular clashes between the army and the insurgents have resulted in a growing number of deaths. July was the deadliest month in almost a year. Crimea remains under Russian control.
Q: How much progress has been made in achieving peace?
A: The leaders of Ukraine, Russia, Germany and France stayed up all night to seal last year's peace accord in the Belarusian capital of Minsk. While the deal halted heavy fighting and set out a path to reconciliation, little has been achieved since. Weaponry initially pulled back has been returned to the battlefield, a full prisoner exchange hasn't taken place and the two sides are at loggerheads over elections and the constitutional status of the rebel-held lands. The United Nations says the death toll is nearing 10,000.
Q: What could be behind the latest tensions?
A: Russia, which holds parliamentary elections in September, says Ukraine wants to destroy Crimean infrastructure and distract its citizens from its own economic travails. Ukraine says that Russia is fabricating a reason to attack it. Analysts say that Putin may want to show Crimeans how important Russia is to their well-being before elections, or is trying to convince the West that Ukraine isn't committed to the peace process, whose implementation is a prerequisite for sanctions relief.
Q: Should we be worried?
A: Russia says the deaths of its servicemen won't go without a response, though what form that response could take remains unclear. While the U.S. and the European Union have urged calm, Russia is bolstering its military presence on its neighbor's border. Ukraine has put its military on alert.
Q: What's next?
A: Mediation by the U.S. and E.U. will now be key to ensuring tensions don't spiral into more deadly violence.
