In an interview with the New York Times last Thursday, Donald Trump remarked that he would not automatically give support to vulnerable members of Nato in the event of a Russian attack.
The implication is that the United States cannot risk its involvement in a dangerous war with Russia to protect distant allies if there is little at stake for the American people.
This is consistent with Trump's isolationist outlook and his apparent hostility to US engagements overseas, suggesting that on foreign policy, he is effectively in the paleoconservative camp.
In recent weeks Trump has gone out of his way to express his support for Israel, applauding settlement building in the West Bank. The Republican Platform Committee has approved a proposal to bin the party's commitment to a two-state solution.
He had spoken just a few months earlier about the importance of being "neutral" in the Israeli-Palestinian conflict.
More significantly, however, his numerous statements casting doubts over the future of Nato and his reluctance to pledge support for vulnerable members of the Alliance raise disturbing questions.
Trump's outspoken support for
Israel appears to be at odds with his comments on Nato. Indeed, his remarks that US allies should pay up for their own security suggest that if he is elected, he could take US policy on Israel in the opposite direction.
Israel is the largest single recipient of American financial assistance but whether US largesse would continue under a Trump presidency is anyone's guess. What happens, for example, if the Iran deal falls through and there is a heightened risk of a dangerous confrontation with Tehran?
If Trump cannot support vulnerable democratic allies that are deserving of support in Eastern Europe, it is far from clear that he would come to Israel's aid if it is attacked.
If Trump were to halt US support for Nato's missile defence system in Europe, will he do the same for the Iron Dome, David's Sling and Arrow defence systems?
Trump's Jewish supporters point out that his daughter has converted to Judaism and married an observant Jew. But that provides no guarantees for Israel. What about those things that he has left unsaid?
Trump is a law unto himself. What he says today can be disavowed tomorrow.
