Sanders is a supporter of American imperialism. Although he boasts
that he voted against the Patriot Act and the Iraq War, he has voted for
numerous defense spending bills and has supported imperialist
interventions under the guise of human rights, including the 1999 NATO
bombing of Serbia and the current war against ISIS.
Sanders supported the US-led regime-change operation, spearheaded by
neo-Nazis, that overthrew a pro-Russian government in Ukraine and
installed a rabidly anti-Russian, right-wing government, which has
carried out a bloody war against pro-Russian separatists in the east of
the country. The US has used its puppet government in Kiev to carry out a
massive US-NATO militarization drive in Eastern Europe, threatening the
outbreak of war with nuclear-armed Russia.
Sanders supports this reckless and reactionary policy, portraying it
as a defensive response to “Russian aggression.” In a 2014 television
interview he declared, “The entire world has got to stand up to Putin.”
-- Tom Hall and Barry Grey, "Is Bernie Sanders a Socialist?" (WSWS).