As NATO faces the challenge of arming Europe, Trump looms large.

Black-clad Turkish police on street corners, giant blue banners reading “Peace Key” and a welcome to Donald Trump.

This may be a NATO summit, but it is the US president who has the metaphorical red carpet rolled out for him.

Trump has made no secret of his disdain for NATO. I only came to Ankara this year because the summit is being held by his friend, Turkish President Recep Tayyip Erdogan, who went to the airport to meet Trump in person.

The two men then walked arm-in-arm as a band played the Stars and Stripes while Turkish Air Force jets made a flypast trailing red, white and blue smoke.

There was always the risk of Trump being disruptive at this meeting. And his inspiring words perfectly captured the carefully crafted picture of unity at this crucial meeting.

Shortly after he landed, he offered a throwaway line that America should indeed take Greenland, a NATO member island that is part of Denmark’s territory.

However, he admitted that his previous thinking on the matter had soured his relationship with NATO. Of course they did.

Denmark’s Prime Minister says that if the United States takes Greenland by force, it will be the end of the alliance.

Then there is Iran. It is clear that Trump is still bitter that his NATO allies did not participate in his election war earlier this year, a conflict that began without consulting the allies that would destroy the global economy.

Sir Keir Starmer has criticized the UK for allowing airstrikes from British airfields on Iranian missile sites.

Referring to the UK prime minister, Trump said: “After the war is over, we will help. No, I said I don’t want that kind of help. We didn’t need any help. I was testing people, trying to see if they were going to be there or not, because I’ve said for a long time that we’re going to help them, but I’m not sure they’re going to be with us.”

The British delegation here was keen to promote defense cooperation with European partners.

But Sir Kiir arrives at the last NATO summit in Ankara, where the defense investment plan has been derided for missing billions of pounds from the requirements set out in last year’s much-lauded strategic defense review.

But beyond the optics and rhetoric, NATO representatives are getting down to the hard work of seeing how Europe’s armaments and defense industries can best cooperate.

Major contracts have been announced for Airbus’ new transport aircraft. NATO’s aging AWACS (Airborne Warning and Control System) early warning aircraft are to be replaced by Swedish GlobeJet aircraft.