WASHINGTON (AP) -- For the second time this year, President Barack Obama will travel to Russia's backyard to assure nervous nations of his ironclad commitment to their security. But his objectives will be clouded by the West's inability to halt the Russian aggression in Ukraine that has stoked fears in other former Soviet republics.<br />
Fighting between Ukrainian forces and pro-Russia rebels continued in eastern Ukraine as Obama prepared to fly to Estonia for meetings with Baltic leaders and to Wales for a NATO summit. The Ukrainian government, NATO and Western nations say Russia has already sent troops, artillery and tanks across Ukraine's southeast border to reinforce the separatists, a claim Russia has denied.<br />
While Obama has warned that Russian President Vladimir Putin could face more economic penalties, he also continues to resist calls for the U.S. to provide military support to help Ukrainian forces push back the Russian incursion.<br />
The president's response to the Ukraine crisis is just one element of a broader foreign policy approach that is drawing criticism from both opponents and allies who fear the White House is being too tentative in the face of global threats.