In his latest attempt to curb and possibly undermine NATO, Donald Trump has said that the defense of the alliance’s newest member Montenegro will “lead to World War III”.

Trying to justify his press conference with Russian leader Vladimir Putin at the Helsinki Summit, Trump appeared on Tuesday night with the pro-Trump Fox TV host Tucker Carlson.

Carlson fed Trump the line, referring to NATO’s Article V for collective defense, “Why should my son go to Montenegro to defend it from attack?”

Montenegro joined NATO last year, defying Russian pressure that allegedly included an attempt to assassinate the Prime Minister and overthrow the government. The southeastern European nation, formerly part of Yugoslavia, has sent troops to the NATO mission in Afghanistan.

Trump ignored this background as he responded:

I understand what you’re saying; I’ve asked the same question. You know, Montenegro is a tiny country with very strong people . . . They are very aggressive people. They may get aggressive, and congratulations, you’re in World War III. But that’s the way it was set up. Don’t forget, I just got here a little more than a year and a half ago.

Article V has been invoked only once since NATO was formed in 1949, in support of the US after the attacks of September 11, 2001.

But last week, as Trump attended the NATO summit in Brussels and visited the UK, his ally and former White House strategist Steve Bannon set up an operations room in London to support the campaign against NATO and the European Union. Trump opened the summit with denunciation of NATO members, especially Germany, and he continued the assault as he stood alongside UK Prime Minister Theresa May.

Senator John McCain rebuked Trump:

Gen. Wesley Clark, a former NATO commander, joined the criticism:

And NATO issued a statement, invoking Trump’s words:

Our collective defence clause, Article Five, is unconditional and iron-clad. It means that an attack on one is an attack on all. President Trump has made clear that the US is fully committed to NATO and our Alliance is stronger than ever.