Ukrainian crisis  is only the latest in a catalog of grievances

Has Russian President Vladimir Putin gone completely mad? This question is actually being debated in serious circles.

In a telephone conversation with President Obama a few months ago, German Chancellor Angela Merkel is reported to have suggested her Russian counterpart is "living in another world."

Just last week, a leaked report commissioned by the U.S. Defense Department in 2008 concluded that the Russian leader may have Asperger's Syndrome, a type of high-functioning autism. The report said it may account for his apparently high degree of control.

A Pentagon spokesman said there was no guidance from the Department of Defense on the report and experts told CNN they were skeptical of the reliability of the Asperger's claim.

For the record, the Kremlin has dismissed the allegation as utter nonsense.

Putin, though, is an enigma.

What does Russia's President Putin really want?