For the United States’ NATO military allies, a good day is a day when President Trump forgets that they exist.

On bad days, he calls the alliance “as bad as NAFTA,” ponders whether it could result in World War III and raises questions about its future. Tuesday probably would fall into the category of bad days for NATO. Yet again, Trump showed that he either doesn’t understand the alliance — or at least ignores everything he knows about it.

During a news conference with right-wing Brazilian President Jair Bolsonaro, Trump said: “I also intend to designate Brazil as a major non-NATO ally, or even possibly — if you start thinking about it — maybe a NATO ally. I have to talk to a lot of people, but maybe a NATO ally.”

This might be an interesting suggestion — if Brazil were located somewhere between Greece and Britain. NATO stands for North Atlantic Treaty Organization and is a European-North American alliance, which is, in many ways, tailored to the two regions. To add Brazil, Trump wouldn’t just have to “talk to a lot of people,” but he also would need to get all NATO member states to agree to change Article 10 of the alliance’s 1949 founding treaty, which states that only European countries can join, besides Canada and the United States.

To be fair, others have similarly suggested that it might be time to modify that part of the treaty and open the alliance to new members such as Australia, Japan and New Zealand. More than a decade ago, James M. Goldgeier, a fellow at the Council on Foreign Relations, wrote that adding new countries from outside Europe could be beneficial, “especially at a time when Europeans are having trouble meeting their own defense commitments.”

But unlike Trump, advocates of changing the founding treaty were arguing in favor of a stronger and emboldened NATO. The president has often appeared interested in achieving the opposite.

Although Trump frequently lashes out at European NATO members for not spending enough on defense, granting membership to Brazil would not be viewed as a way to correct the balance sheet — but instead as another attempt by Trump to disrupt the alliance. Some of his remarks have raised doubts about the core principles that underpin the alliance’s mechanisms, and members would approach any Trump suggestion with caution.

”Unlike every president since 1949, President Trump has been inconsistent and unpredictable regarding his commitment to NATO, leaving allies in doubt. So, suggesting offhand a change that would require American leadership to gain consensus to revise the treaty seems a reach,” said Douglas Lute, who was the U.S. permanent representative to NATO between 2013 and 2017.

Even if the founding treaty were changed in Trump’s favor, the United States would not be able to add countries by itself, but would need the approval of all other members. Nations such as France and Germany probably would object to welcoming a right-wing president who has been accused of attacking democratic institutions and whose polices may violate NATO accession rules.

“I don’t see any NATO nation agreeing to such a change and then allowing Brazil into the alliance, as it would mean them giving Brazil a security guarantee,” said Ivo H. Daalder, president of the Chicago Council on Global Affairs and a former U.S. permanent representative on the NATO Council.

“While Brazil might become a major non-NATO ally of the United States, it certainly won’t become a member of NATO,” political scientist and defense expert Marcel Dirsus agreed.

NATO responded to a request for comment by referring all queries to “U.S. authorities.”

Since Trump’s inauguration, the alliance has dealt more with questions of financing than with concerns about the state of democracy among its members. “Trump has long made clear that he doesn’t believe in alliances as mutual security organizations but sees these relationships mainly, if not solely, in terms of an economic transaction — where allies should pay the U.S. for promising to defend them,” Daalder said.

In March 2017, Trump set a tense tone for future NATO discussions by accusing Germany of owing the United States “vast sums of money” for NATO, because it spends far less per capita on defense than other allies do.

Experts and government representatives swiftly rejected the criticism, with German Defense Minister Ursula von der Leyen saying, “NATO does not have a debt account.” Unlike what Trump suggested, member states do not pay NATO except for a small logistical budget. Instead, member states commit to independently spend at least 2 percent of their gross domestic product on defense and agree to intervene should any of their allies be attacked.

Many NATO members do not meet that threshold. Neither does Brazil.

Michael Birnbaum in Brussels contributed to this report.

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