While international condemnation of Russian President Vladimir Putin is likely to increase after a Malaysia Airlines jet was shot down this week, it's unclear whether such pressures will be enough to cause the leader to abandon his campaign of meddling in eastern Ukraine.
Malaysia Airlines Flight MH17 — en route from Amsterdam to Kuala Lumpur with 298 on board — crashed in a rebel-held area of eastern Ukraine on Thursday. According to the U.S. military, the jetliner was shot down by a surface-to-air missile, likely by separatists supplied and trained by Russia.
"Putin is cornered like never before, and the question is how he behaves," says Anders Aslund, a senior fellow with the Peterson Institute for International Economics in Washington, D.C. "He needs to do something not to become a complete pariah."
Condemnation has been swift since it became clear the Malaysian jetliner was shot down, but world leaders have yet to take concrete action.
Ian Brzezinski, who served as deputy assistant secretary of defense for Europe and NATO Policy under former president George W. Bush, says the USA and Europe should bolster Ukraine's military with more advanced anti-tank weapons, surface-to-air missile, intelligence and advisers, while also dramatically increasing sanctions on Russia.
"This is an incident where Putin now has blood on his hands that is the blood of Westerners," he said. "We should hit the Russian economy hard … Incremental steps are not going to be sufficient."
At the crash site, there are signs Russia and its separatist allies in Ukraine may be trying to obstruct the investigation.
On Saturday, Ukraine charged that separatists had removed at least 38 bodies from the crash site and accused Russia of helping rebels destroy evidence. Rebel leaders denied such charges and said they were encouraging the international community to help with the cleanup.
Michael Bociurkiw, spokesman for the Organization for Cooperation and Security in Europe, told reporters that the 24-member monitoring delegation's movements were being limited by rebels at the crash site Saturday and that the team was unable to conduct a full-scale investigation.
"We have to be very careful with our movements because of all the security," Bociurkiw said. "We are unarmed civilians, so we are not in a position to argue with people with heavy arms."
Meanwhile, U.S., Ukrainian and other Western officials have pointed at intercepted conversations and rebel social media posts that provide strong evidence that a surface-to-air missile fired by pro-Russian separatists brought down the plane.
It is also unclear who is in possession of the flight's black boxes. Igor Strelkov, a rebel military commander in the Donetsk region, reported on his website that eight of the aircraft's 12 recording devices had been recovered but later denied having them.
Brzezinski says the incident is only a "potential game changer" because it depends on how the West will respond.
"If the West sticks to its previous path of slowly ratcheting up sanctions, (Putin) is going to stick to his previous course, which is escalations," Brzezinski said. "Every time we've ratcheted up sanctions, Russia's reaction has been to provide more assistance to separatists."
The airline disaster will create a moment of unity in the West, but it's not clear for how long, says Toby Gati, who helped shape U.S. policy toward Russia during Bill Clinton's first term as president.
"There will be that moment when everyone will be focused on getting to the crash site and finding out what happened," Gati said.
But it might take a much longer time for Europeans to "overcome their fear of losing access to Russian gas" and to consider additional steps to sanction Russia, she said.
"The situation on the ground in Ukraine changes so quickly that it's been hard to form a clear picture of the level of Russian involvement," Gati said, adding it will take a long time and a real commitment from the USA to help Europe improve its energy independence.
Putin is likely to adjust his reaction based on European and U.S. behavior, says Steven Pifer, who helped shape U.S. policy on Russia and Ukraine in the administrations of former presidents George W. Bush and Bill Clinton.
"Putin is calculating how much blowback will there be from the international community," Pifer said. "He's going to look mainly at Europe."
Putin will not be happy to find out that German Chancellor Angela Merkel urged France on Friday not to move ahead with the sale of two aircraft carriers to Russia, Pifer said.
"If this event triggers a decision in Europe to take sanctions way beyond what Europe and the United States have done to date, Putin will consider whether to change course," he said. "This is a moment for the international community to talk about seriously hitting Russia with much stronger sanctions."
But even then, it's not clear how Russia will respond.
"(Putin) likes to keep a lot of options open but also watches to see what the other guy's going to do, and how to make that turn to Russia's gain," Pifer said.