Obama turned out, on taking office, to have a hard time saying good-bye to the occupation of Iraq, only leaving when he was forced out by an Iraqi government that refused to continue giving US forces legal immunity for killing Iraqi civilians. In Afghanistan, he decided to copy the same "surge" -- a massive increase in targeted assassinations and violence -- that he had once condemned in Iraq. Then he stepped up drone-launched rocket attacks and bombings in seven other countries. 

More recently he has begun an air war against Syria (okay, he says it's against the so-called Islamic State, but the whole world, with the exception of a lot of ill-informed US citizens, knows it's ultimately against the Syrian government), and now his Secretary of Defense (sic) Ashton Carter and his Secretary of State John Kerry are pushing for sending heavy arms and, inevitably, US "advisors" to Ukraine to escalate US involvement in the civil war there. What makes that latest war particularly dangerous is that all the while, Peace Laureate Obama makes it clear that the "enemy" is Russian President Vladimir Putin and the Russian military.