Five sources told Politico on Monday that US Secretary of Defense Jim Mattis, national security adviser H.R. McMaster, and Secretary of State Rex Tillerson worked with Trump on his NATO speech for weeks and pushed hard for the Article 5 language to be included.
But it was removed from his speech, possibly by Trump, himself, just before he delivered it.
When President Donald Trump addressed NATO leaders during his debut overseas trip little more than a week ago, he surprised and disappointed European allies who hoped—and expected—he would use his speech to explicitly reaffirm America’s commitment to mutual defense of the alliance’s members, a one-for-all, all-for-one provision...
[T]he president also disappointed—and surprised—his own top national security officials by failing to include the language reaffirming the so-called Article 5 provision in his speech.Trump's top advisers thought it was in the speech and, according to Politico, a White House aide even told The New York Times the day before the line was definitely included.
It was not until the next day, Thursday, May 25, when Trump started talking at an opening ceremony for NATO’s new Brussels headquarters, that the president’s national security team realized their boss had made a decision with major consequences—without consulting or even informing them in advance of the change.-RW
“They had the right speech and it was cleared through McMaster,” said a source briefed by National Security Council officials in the immediate aftermath of the NATO meeting. “As late as that same morning, it was the right one.”...
Added a senior White House official, “There was a fully coordinated other speech everybody else had worked on”—and it wasn’t the one Trump gave. “They didn’t know it had been removed,” said a third source of the Trump national security officials on hand for the ceremony. “It was only upon delivery.”
The president appears to have deleted it himself, according to one version making the rounds inside the government,..another version relayed to others by several White House aides is that Trump’s nationalist chief strategist Steve Bannon and policy aide Stephen Miller played a role in the deletion.
Also see: What is Article 5?