At a recent campaign rally, Donald Trump defended Saddam Hussein's record on terrorism, noting that the late Iraqi leader was a "bad guy" who was nevertheless efficient at "killing terrorists." House Speaker Paul Ryan immediately distanced himself from Trump's remarks, and leading Republican donors jumped in with criticism as well.

In his campaign, Trump has repeatedly angered Washington's Republican foreign policy establishment with his views on America's role in the world. Although Trump did not repeat these views during his nomination speech on Thursday, in an interview Wednesday he suggested he might revisit the United States' willingness to defend its NATO allies — drawing a rebuke from Republican Sen. Lindsey Graham.

Some of Trump's foreign policy ideas are downright dangerous. Two of his ideas, for instance — forcing Mexico to pay for a new border wall and banning Muslims from entering the U.S. — alienate much of the world and neither reflect American values nor promote American interests. His apparent enthusiasm for increasing the U.S.' use of torture is downright chilling. Nevertheless, amid Trump's showboating and frequent stream of consciousness thoughts, he raises some critical questions that challenge the longtime Washington foreign policy consensus but deserve to be taken seriously.