As President Barack Obama travels through Asia this coming week, he will confront a region that's warily watching the crisis in Ukraine through the prism of its own territorial tensions with China.
Each of the four countries on Obama's itinerary - Japan, South Korea, Malaysia and the Philippines - has a dispute with Beijing over islands in the South and East China Seas. Their leaders will be weighing Obama's willingness to support them if those conflicts boil over.
''What we can say after seeing what happened to Ukraine is that using force to change the status quo is not acceptable,'' said Japanese Prime Minister Shinzo Abe, whose country is in one of the fiercest disputes with China.
Administration officials, including Defense Secretary Chuck Hagel, have taken a tougher line on the territorial issues in recent weeks, sternly warning China against the use of military force and noting that the U.S. has treaty obligations to defend Japan in particular. But in an attempt to maintain good relations with China, the U.S. has not formally taken sides on the question of which countries should control which islands.
Analysts say there are concerns that China could be emboldened by the relative ease with which Russia annexed the Crimean Peninsula from Ukraine over U.S. objections, as well as the very real possibility that Moscow could take more land. Moreover, some in Asia question Obama's ability to follow through on his security pledges in light of his decision last summer to pull back on plans for a military strike against Syria.
''The heavyweights in the region got very scared by the Syrian decision,'' said Douglas Paal, a longtime U.S. diplomat in Asia who now is vice president of the Carnegie Endowment for International Peace. ''They've never seen anything like that. They've always counted on strong executives bringing the Congress along or going around the Congress to make sure that our security guarantees will be honored.''
Obama's advisers say they see little evidence thus far that China has been encouraged by Russia's incursions into Ukraine. Instead, they say Beijing appears to be viewing with concern the Kremlin's attempts to sway pro-Russian populations in areas of Ukraine, given China's own restive minority populations in border regions.
U.S. officials also have tried to keep China from supporting Russia's moves in Ukraine by appealing to Beijing's well-known and vehement opposition to outside intervention in other nations' domestic affairs. Officials