The president says if Russia continues in its path in Ukraine the US will be "forced to apply costs" to Moscow.
"The problem is we don't have a lot of trade with Russia," said Nancy Soderberg.
Soderberg is a distinguished visiting scholar at the University of North Florida and a former United States ambassador to the United Nations. She says if the Congress decides to impose tough economic sanctions against Russia, it would be a significant step. But she wonders if it would be enough to make Russian President Vladimir Putin back down in Crimea.
"We can't wave a magic wand and tell President Putin what to do."
But she does feel if the rest of the international community gets involved, that could have an impact on Putin's decisions.
She says, "It's pretty clear the Russians are thumbing their noses at the international community. They are going to go ahead and annex part of the Ukraine in a way that is not going to be recognized by the international community."
On Wednesday, a senate foreign relations committee passed a measure that would impose tough economic sanctions on those individuals in Russia who are involved with the Russian military's intervention in Crimea. The bill also provides one billion in loan guarantees for the new government in Ukraine.
But Soderberg says there are still a lot of unaswered questions.
"Whether the former head of Ukraine that has now fled will be extradicted back to Ukraine to stand trial. Thats what the people are going to want. I think the Russians are unlikely to send him back."
She ponders whether Russia will try to intervene in the new government.