BRUSSELS (Reuters) - Donald Trump’s portrayal of NATO as an alliance in crisis has raised concern that the U.S. president’s nagging criticism might erode U.S. public support and risk America’s commitment to collective defense, diplomats said.

U.S. President Donald Trump arrives to hold a news conference after participating in the NATO Summit in Brussels, Belgium July 12, 2018. REUTERS/Reinhard Krause

Allies emerged confused and shaken from a two-day NATO summit in which Trump harangued them over perceived under- spending on defense, accused Germany of being a prisoner to Russian energy and prompted an emergency meeting of leaders trying to contain the fallout from the unexpected tirade at one session.

NATO diplomats complained that the drama around Trump’s forthright comments had overshadowed big decisions that the allies took in areas from defense spending to new weapons and strategies to address Russia’s efforts to destabilize the West through cyber and covert attacks.

“There was a gap between the Trumpian-generated idea that there is some kind of crisis and the reality that this was one of the most substantial summits for years,” one senior NATO diplomatic source told Reuters.

Having questioned the value of NATO in tweets throughout the summit, Trump later told reporters that the 29-member military alliance “was not doing what they were supposed to be doing” until he came to Brussels and that he was “extremely unhappy” until his intervention.

Then he claimed “total credit” for increases in defense spending, although they were in fact agreed in 2014, and warned that “NATO is helping Europe more than it is helping us,” in language that did not make a public case for unity.

However, the summit also agreed on a new training mission for Iraq, an invitation for Balkan state Macedonia to join NATO and more funding for troops in Afghanistan.

While Trump did let the 79-point summit declaration go through, his assertion that “I’ve taken over a lot of bad hands and I am fixing them,” at the end of the summit left the impression there were serious problems at NATO, diplomats said.

NATO may now need its friends in the U.S. Congress and in the Republican and Democratic parties to speak out more to prevent permanent damage to alliance’s image in the United States, they said.

The U.S. Senate overwhelmingly approved a motion in support of NATO on the eve of this week’s summit, and former U.S. Secretary of State John Kerry called for more.

“Enough,” the Democrat said of Trump’s style at the summit. “This isn’t good for the United States and there are people across the aisle - as the Senate vote yesterday clearly showed - who know it and need to say it,” Kerry said on Twitter.

PERCEPTION, REALITY

The summit decisions, agreed by all 29 allied governments, won hardly any sustained public attention and the underlying unity was undercut by Trump’s claims he had won new pledges in defense spending, forcing the French and Italian leaders into denials that dominated post-summit news conferences.

He reiterated that claim in Britain on Friday.

“The concern is that this is not just noise to disregard, because perception is reality and this president may be with us for another six years,” the senior source said.

NATO, founded in 1949 to contain a military threat from the Soviet Union, relies on the United States’ military superiority to face down a host of threats on Europe’s borders, including a resurgent, nuclear-armed Russia and militant attacks.

A commitment to defend each other is the bedrock of the alliance and any suggestion that the United States would not come to Europe’s aid because, as Trump has suggested, they owe “massive” sums, could be a blow to its deterrence.

“President Trump has not taken damaging actions against NATO, but his words are damaging,” said Adam Thomson, a former British ambassador to NATO and now director of the European Leadership Network think-tank in London.

Having lambasted NATO for failing to reach a target of 2 percent of national income on defense, Trump told fellow leaders in Brussels he would prefer a goal of 4 percent, similar to U.S. levels, and then claimed victory for forcing countries to move.

He also said he expected an easier meeting with Russian President Vladimir on Monday in Helsinki in remarks that contrast with the West’s accusations that Moscow is seeking to undermine European democracies.

NO MORE SUMMITS?

One option aired by diplomats is to scrap regular NATO summits altogether and return to the era of the 1980s, when such leaders-level gatherings were less common and when much of the decision-making was taken by defense and foreign ministers.

But Thomson said that was not realistic. “You cannot ignore Trump, he will find a way to make himself heard.”

Some European officials feel strongly that NATO should be more confident in calling out Trump’s mis-statements about the alliance.

Trump’s claims that the United States pays for 90 percent of European security and NATO are incorrect, NATO data shows.

While U.S. defense spending makes up 70 percent of combined allied governments’ military budgets, just 15 percent of U.S. expenditure is spent in Europe on NATO-related defense.

Washington pays about 22 percent of the running cost of NATO, including the headquarters and commonly-funded equipment such as AWACS surveillance planes.

Trump has also claimed Germany and others owe money to the United States and NATO, but allied contributions are voluntary and there are multiple budgets.

At 3.5 percent, the United States’ own annual defense spending is below the 4-percent-of-GDP level that Trump has said it is, NATO figures show.