DC Decoder Ukraine crisis: How far will Obama go to get Russia to back down?

President Obama and four other western leaders agree to tougher sanctions on Russia. But Mr. Obama is unlikely to go further, as he aims to avoid a proxy war with Russia.

By , Staff writer

Jacquelyn Martin/AP

The United States has released what it says is photographic evidence of Russia shelling targets in Ukraine from its side of the border, and senior US officials are telling their Russian counterparts the US has proof of the Russian military’s growing involvement in Ukraine.