The Russian opposition figure Alexei Navalny recently said that were it not for Western economic sanctions, Russian tanks would already have swept west to the port city of Odessa, occupying a huge swath of southern Ukraine and cutting off the rest of the country from the Black Sea. He's probably right, yet it won't count for much if Ukraine's government doesn't take advantage of the respite sanctions have provided by changing course.
Russian President Vladimir Putin has in recent weeks rekindled the war in Eastern Ukraine, and it's important to understand the role that Ukrainian actions have played in this. It's equally important to recognize that sanctions can't defeat Putin; they can only make him more cautious and open to a settlement.
It was just last September that Putin initiated the Minsk cease-fire agreement, halting his tanks after they had reversed many of the gains Ukraine's military had made against Eastern separatists over the summer. And it's a fair assumption that Europe's threat to impose heavier economic sanctions influenced his decision to stop his advance.