U.S. President Donald Trump has shaken seven decades of American defense policy by criticizing the North Atlantic Treaty Organization. Trump maintains that the military alliance connecting the U.S., Canada and Europe needs to focus more on fighting terrorism and that most NATO nations fail to pay their “fair share” for the common defense. The U.S. bears the heaviest military costs. Trump put on a stark display of sourness during his inaugural visit to NATO in 2017, when he tried to browbeat members into expanding their defense spending and left some questioning the U.S. commitment to the alliance’s key doctrine that an armed attack against any member is considered an attack against all. NATO members are bracing for Trump’s return at a July 11-12 summit.

1. What’s the point of NATO?

Since it was founded in 1949 to protect Europe against Soviet attack during the Cold War, NATO has expanded its role to include bombing Serb forces during the Bosnia and Kosovo wars of the 1990s, enforcing an arms embargo on Libya in 2011, helping Europe tackle a flood of Middle Eastern refugees that erupted in 2015, and stepping up cyber defense. In addition, since Russia’s encroachment in Ukraine in 2014, the alliance has refocused on the military threat from Moscow, deploying multinational battle groups in eastern Europe to reassure allies there and upgrading its command structure for the first time since the end of the Cold War. All the while, NATO’s membership has grown from 12 to 29 countries, with Montenegro joining in June 2017.

2. How is NATO funded?

Two ways. Countries make contributions based on their gross national income to finance NATO’s own budget, which amounts to 2.3 billion euros ($2.7 billion) for 2018 and covers the alliance’s headquarters, its integrated command and its own limited military capabilities. But most of NATO’s capacity comes from the armed forces of member nations. In 2006, members set a “guideline” to spend at least 2 percent of their gross domestic product on defense. In 2014, they agreed to “aim to move towards” the target by 2024.

3. Has the U.S. always spent more on defense?

Yes, but the imbalance has grown. Military spending increased in the U.S. following the terrorist attacks on Sept. 11, 2001, and decreased in Europe after the Cold War ended in 1990 and again after the financial crisis broke out in 2008. Over the past 20 years, the U.S. share of defense spending by NATO members as a whole has risen to 72 percent from 58 percent.

4. Do members owe money from past years?

No. Trump has said NATO allies that have failed to meet the 2 percent spending guideline in past years owe “vast sums” or “massive amounts” to NATO. This is untrue because the spending goal is just that, not a legally binding commitment.

5. What do states that spend less than 2 percent say?

The sharpest response has come from Angela Merkel, chancellor of Germany, which spends about 1.2 percent of GDP on defense and aims to boost such outlays to 1.5 percent by 2024. Merkel has insisted on looking beyond purely military expenditure when considering the NATO target. She argues that because development aid is vital to security, it should be included in contributions toward the common defense. Germany spent 0.7 percent of gross national income on such assistance in 2017, compared with 0.2 percent by the U.S., according to the Organization for Economic Cooperation and Development. In addition, NATO members are focused on smarter spending to improve actual military capabilities, complicating how to measure a “fair” contribution.

6. What is NATO’s role fighting terrorism?

After the Sept. 11 attacks on the World Trade Center and the Pentagon 17 years ago, NATO invoked its collective-defense clause for the first and so far only time. Since then, the alliance has gradually boosted its anti-terrorism activities. That first operation, which involved the use of Airborne Warning and Control System planes to help patrol the skies over the U.S., was followed by ship monitoring in the Mediterranean Sea, participation in the war in Afghanistan, and the training of Iraqi soldiers. Most recently, NATO leaders decided in May 2017 to make the alliance a full member of the international coalition fighting Islamic State in Iraq and Syria.

7. What more does Trump want?

With Estonia, Greece, Poland and the U.K. being the only European members of NATO that met the 2 percent spending goal in 2017, Trump has pressed for firmer signals that other allies will ramp up defense outlays. To that end, the alliance’s leaders agreed at their summit last year to draw up annual plans for increased spending. European members and Canada will boost their combined military outlays for a fourth year in 2018, NATO Secretary General Jens Stoltenberg said on June 7.

8. Why is there concern over Trump’s commitment to NATO?

During his election campaign, Trump alarmed U.S. allies in Europe by suggesting the U.S. commitment to defend fellow NATO countries should depend on whether their military spending was high enough. European nations seeking a reassurance on this point were disappointed at the May 2017 Brussels summit, where Trump refused to offer an explicit endorsement of NATO’s collective-defense clause. Instead, he hectored fellow leaders to pay more for defense. Two weeks later, in a press conference in Washington, Trump said he was “absolutely” committed to the clause.

9. Why is the mutual-defense doctrine so important?

The principle, enshrined in Article 5 of the NATO treaty, enhances the credibility of the alliance’s deterrence strategy by increasing the risks for any potential aggressor. More generally, the doctrine has symbolized an underlying partnership between North America and Europe based on shared political and economic values. With Russia challenging the security order in Europe, NATO’s European members consider Article 5 to be as relevant as ever.

• A Foreign Policy article on NATO’s May 25 summit.

• A Pew Research Center survey showing an improved NATO image.

• A Bloomberg News story from 2015 on NATO’s eastern defense plan.

--With assistance from Anne Cronin.

To contact the reporter on this story: Jonathan Stearns in Brussels at jstearns2@bloomberg.net

To contact the editors responsible for this story: Alan Crawford at acrawford6@bloomberg.net, Lisa Beyer, Richard Bravo

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