Stakes high for Obama and Putin amid fallout from shooting down of MH17
The downing of an airliner has led to a war of words, but with dilemmas facing both US and Russian leaders, what will either do next?
The shooting down of a passenger jet over separatist-controlled territory in eastern Ukraine has already led to a war of words.
But when it comes to responding with actions, both Barack Obama and Vladimir Putin have been left with tough choices to make.
Despite levying six rounds of increasingly tough economic sanctions against Russia for its actions in Ukraine, the US president has left two rich targets untouched: Moscow's natural gas export behemoth and its main weapons exporter.
Financial warfare against Gazprom or Rosoboronexport could invite Russian retaliation against America's European allies and negative consequences for Washington - highlighting the dilemmas Obama faces as he weighs how to respond to the downing of the Malaysian airliner on Thursday.
"The problem is that there are really limits on what Obama can do," said Matthew Rojansky, a Russia expert at the Wilson Centre think tank in Washington. "Even if the impulse is to punish the Russians, you can only go so far in hitting them because of the wider repercussions" for European energy supplies and the global economy.
US officials said they suspected the Malaysia Airlines tragedy was the work of Moscow-backed rebels in Ukraine and that they hoped it would unite the 28-member European Union, whose sanctions on Russia have lagged well behind Washington. On Obama's orders, the US Treasury has carefully tailored sanctions to inflict maximum pain on Putin's inner circle and entities backing the Ukrainian rebels, while minimising the damage to European economies and American business. Republican critics have accused him of being too restrained towards Russia.