Donald Trump and NATO: Why His Silence on Article 5 Is a Big Deal

``Trump railed against [the NATO members' defense spending] shortfall Thursday, telling the audience in Brussels that it was "not fair to the people and taxpayers of the United States." His words echoed those of President Barack Obama, who just last year accused NATO members of being "complacent" and told them to dig deeper into their wallets. What's different with Trump is that no other president has accompanied this plea with an ultimatum: Pay up or we won't protect you.''