After calling Iran's threats to Israel "unacceptable" Tuesday afternoon, Trump tweeted, "In order to get elected, @BarackObama will start a war with Iran."
Trump has questioned Obama in the past, once asking how the president was admitted to two Ivy League schools -- Columbia University and Harvard Law School. He also famously questioned whether Obama's presidency was valid, arguing that Obama had never produced documentation to prove he was born in the United States.
Obama gave Trump a taste of his own medicine at the 2011 White House Correspondents' Dinner, which took place the same week the state of Hawaii released the president's official birth certificate. The president took a dig at Trump's lack of political background, saying "we all know about your credentials and breadth of experience."