• Date: March 2014

Vladimir Putin's decision to invade and ultimately annex Crimea brought U.S.-Russia tensions to levels unseen since the Cold War.

U.S. investors were briefly worried that the Ukrainian conflict would spark a broader war or massive sanctions that could hurt global markets. The U.S. stock market bobbled several times in March and April as the tensions escalated.

Those concerns faded a bit, but have not gone away, as the developments in the region this week show.

NEXT: Yellen's rookie mistake