Billionaire developer Donald Trump, who is hinting at a presidential run as a Republican, said Wednesday he has a "foolproof" plan to defeat the Islamic State (ISIS), but won't share it unless he is elected."I do know what to do, and I would know how to bring ISIS to the table or, beyond that, defeat ISIS very quickly," Trump said on Fox News Channel's "On the Record with Greta Van Susteren." "And I’m not gonna tell you what it is tonight."Host Greta Van Susteren immediately asked, "Why won’t you tell? We need all the help we can get.""I don’t want the enemy to know what I’m doing," Trump replied. "Unfortunately, I’ll probably have to tell at some point, but there is a method of defeating them quickly and effectively and having total victory."Trump criticized President Barack Obama for going "on television to explain exactly when we're going to attack a certain city, what we're going to do, what hour we're going to be using for the attack, how many are going."He said Gens. Douglas MacArthur and George Patton are "spinning in their grave" over how the United States gives all the details of its military operations upfront."If I run and if I win, I don't want the enemy to know what I'm going to do," Trump said."All I can tell you is it is a foolproof way of winning."