By Sruthi Shankar and Anisha Sircar (Reuters) -Europe’s top equities benchmark plummeted nearly 4% on Monday, pulled down by worries about a Russian attack on Ukraine and the possibility of a more hawkish U.S. Federal Reserve this week. The Europe-wide STOXX 600 index fell 3.8%, marking its worst day since June 2020. The United States said on Sunday it was ordering diplomats’ family members to leave Ukraine, in one of the clearest signs yet that American officials are bracing for an aggressive Russian move in the region. “It has been a brutal start to the week for stocks,” said Chris Beauchamp…