Why will these sanctions against Russia work?

Announcing new sanctions against Russia on Tuesday, President Barack Obama insisted that "this is not a new Cold War."

"It didn't have to come to this," Obama said from the White House. "It does not have to be this way. This is a choice that Russia and, in particular, President Putin has made."

Since MH17 was shot out of the sky, the fighting between Ukraine and Russian-backed separatists has only gotten worse. The violence creating a virtual force-field around the crash site.

But with round after round of sanctions targeting Russia, what makes the Obama administration believe these new punishments will be any different?

State Department spokeswoman Marie Harf spoke to CNN's Jake Tapper about why the government believes Putin will finally be forced to maneuver.