A quarter-century after the fall of the Soviet Union, authoritarian rulers such as Vladimir Putin and Bashar Assad are showing they can and will defy international norms, suppress dissent and use military force. American policymakers are struggling with how to respond.

"It's a big philosophical question about how to deal with a strong state with anti-Western and autocratic proclivities," said Michael McFaul, the most recent American ambassador to Moscow. "I would say on that score we are kind of confused as a country."

Citing the sweeping unpopularity of the wars in Iraq and Afghanistan, U.S. officials have embraced economic sanctions as their primary means of pressuring foreign governments. In an interconnected, 21st-century global economy, President Barack Obama argues, economic sanctions are more powerful than ever.