After Trump's claims, here's what to know about NATO member defense spending

Former President Donald Trump's remarks over the weekend that he would "encourage" Russia "to do whatever the hell they want" to NATO allies that fail to meet defense spending guidelines have raised a lot of questions and drew rebuke from the White House and NATO's leader.

"You don't pay your bills, you get no protection. It's very simple," he said at a campaign event in Conway, South Carolina.

While multiple Republican senators backed Trump's remarks, President Joe Biden called Trump's comments "shocking" and "un-American," adding that the commitment to NATO is "sacred."

Trump's comments put the safety of U.S. troops and their allies at risk, NATO Secretary-General Jens Stoltenberg said in a statement.

The Republican presidential front-runner's remarks raised questions about NATO's guidelines on defense spendings and how much each ally country contributes to NATO's military efforts.

NATO data show that almost all allies are expected to meet the defense spending guidelines in 2024 -- contrary to Trump's comments.

Here's what else to know about NATO defense funding.

What is NATO and who are its members?

The North Atlantic Treaty Organization, or NATO, is a political and military alliance formed in 1949 in the aftermath of World War II. Started with only 12 members, the alliance expanded to 31 nations and now includes European countries such as Turkey and Iceland, Canada and the U.S.

One of the prominent clauses of NATO's treaty is Article 5, which deals with collective defense, which says that any attack on a member country is an attack on all of the countries in the alliance, according to its website. Article 5, which is not enforced automatically, but requires agreements from all allies, was invoked only once after the 9/11 attacks on the U.S.

How does NATO fund its defense?

NATO allies choose to contribute troops and funding to the alliance; how much each country would spend on its defense is voluntary. However, the nations set defense spending standards and guidelines for themselves to ensure the alliance's military preparedness, according to NATO's website.

NATO leaders pledged in 2014 to commit at least 2% of their gross domestic product to defense spending, in response to Russia's annexation of Crimea and instabilities in the Middle East. The agreement was renewed in 2023, NATO said on its website.

These are not funds that countries would pay to NATO, but contributions to their own military budgets. The alliance doesn't have its own army and its military protections are insured by member countries, according to NATO's website.

In addition, the countries agree to dedicate 20% of the defense budget to equipment expenses, including research and development, to keep up with modernization in the military field, according to the funding section on NATO's website.

Which NATO countries meet those guidelines?

Only 11 of the 31 nations were predicted to spend more than 2% of their GDP on defense in 2023, according to NATO estimates published in July. Almost a decade ago, only three countries met that mark.

Even more NATO countries are estimated to meet the 2% threshold in 2024. All European allies are expected to spend 2% of the GDP in 2024 for the first time ever, Stoltenberg said.

Ahead of a Thursday meeting between NATO defense ministers, Stoltenberg released the latest spending numbers, which he called an "unprecedented rise."

"We are making real progress: European Allies are spending more," he said in the release. "However, some Allies still have a ways to go."

In addition to reaching the 2% threshold, all the NATO countries spent more than 20% of their estimated 2023 defense budgets on equipment, meeting that guideline from the 2014 agreement.

How much does the U.S. contribute to NATO's defense?

The U.S. was estimated to spend 3.49% of its GDP in 2023 on defense, which is roughly $860 billion. Poland comes in first with 3.9% -- more than $29 billion. The only other country estimated to pass the 3% mark was Greece, with more than $7 billion.

The U.S. allocates almost twice as much of its GDP -- $860 billion -- as European allies and Canada do together -- roughly $404 billion. The U.S. contribution makes up two thirds of the total NATO defense expenditures. This has been the case since the alliance was founded. U.S. defense spending also saw a major increase after the 9/11 attacks.

The other top contributors are Germany and the United Kingdom, with each making up more than 5% of total NATO defense spending. While the U.K has allocated more than 2% of its GDP in the last two decades to military spendings, Germany falls below the 2%.

Editor's note: This story has been updated to reflect that the GDPs of the nations mentioned are in billions of dollars.