WASHINGTON — President Obama has a variety of ways he can make good on his threat to make Russia pay "costs" for its military intervention in Ukraine.
But it's not clear any of them will make a difference to Russian President Vladimir Putin, or whether they might simply underscore the United States' relatively weak hand in the unfolding Ukraine crisis.
The U.S. and its European allies can take steps to isolate Russia diplomatically, which would undermine Putin's claim that his country is again ascendant as a world leader. They can also take steps that would pinch the Russian elite, which relishes its access to Western Europe.
Some of the moves would...