History's most enduring multi-nation military alliance turned 70 Thursday, but it was a milestone more notable for festering disputes than celebrations of harmony.
Formed to protect a World War II-ravaged Europe in the throes of a Cold War with the Soviet Union, the North Atlantic Treaty Organization is now grappling with ongoing uncertainty about the United States' commitment to its leading membership in NATO, questions about burden-sharing fairness and criticism of the growing ties of some members with longtime adversaries.
The organization's original mission was clear. In the words of Lord Hastings Lionel Ismay, NATO's first secretary general, the alliance was created "to keep the Soviet Union out, the Americans in and the Germans down."
Today, with the Soviet Union long gone and Germany reluctant to boost modest military outlays, NATO continues to fret about keeping America in and keeping Russia out. Here's a look at five dark clouds hanging over NATO as it enters its eighth decade.
Mixed signals from NATO's most powerful member
Washington is where the treaty that established NATO was signed by its 12 original members. There are now 28 nations in the alliance in addition to the United States, but they sent only their foreign ministers — and not, notably, their heads of state or government — to the American capital for the 70th anniversary.
It was a move that ensured President Trump, an unapologetic critic of NATO, would not appear. When Vice President Mike Pence told the assembled NATO foreign ministers on the eve of the anniversary that "NATO is stronger today because of the commitment of our allies but also because of the resolute American leadership of President Trump," he failed to muster a single clap of applause.
The visiting top diplomats were certainly aware of reports that in meetings with his advisers over the past year, Trump had repeatedly broached pulling out of NATO.
It's the U.S. Congress that's taken the lead in reassuring NATO that the United States remains committed to the alliance. In January, the Democratic-led House overwhelmingly approved legislation that prohibits the expenditure of any funds on a U.S. withdrawal from NATO.
At the invitation of House Speaker Nancy Pelosi and Senate Republican Majority Leader Mitch McConnell, Jens Stoltenberg on Wednesday became the first NATO secretary general to address a joint meeting of Congress, an honor that also served as a rebuke to Trump's jabs at NATO.
Bad blood over defense spending
Tensions between the U.S. and its NATO allies over their defense spending levels are at their highest level in decades. After Russia annexed Crimea in 2014, those allies made a commitment to boost their defense expenditures to at least 2 percent of their gross domestic product by 2024. Only seven of Washington's 28 NATO partners have reached or surpassed that target.
While speaking to the foreign ministers gathered for the anniversary, Pence specifically name-checked Germany for planning to spend 1.3 percent of its GDP on defense this year.
"It is simply unacceptable," Pence scolded, "for Europe's largest economy to continue to ignore the threat of Russian aggression and neglect its own self-defense and our common defense at such a level."
Turkey arms purchase standoff
Turkey has been a member of NATO since 1952; it has the second-largest military in the alliance after the U.S. and is valued as a key strategic linchpin as a nation bordering the Black Sea, the Mediterranean and the Middle East. But the U.S. is in a quickly escalating standoff with Turkey over Ankara's decision to buy Russia's S-400 air defense missile system - an acquisition that the U.S. insists would endanger the fleet of 100 F-35 stealth jet fighters that Turkey plans to buy from the warplane's manufacturer, Lockheed Martin Corp.
"Turkey's purchase of a $2.5 billion S-400 anti-aircraft missile system from Russia poses great danger to NATO and to the strength of this alliance," Pence told the alliance's assembled foreign ministers, among them Turkey's Foreign Minister Mevlut Cavusoglu. "If Turkey completes its purchase of the Russian S-400 missile system, Turkey risks expulsion from the joint F-35 program."
That threat from Pence came hours after Cavusoglu declared in an interview at the Washington-based Atlantic Council, "S-400 is a done deal and we will not step back on this."
Trump's decision in February to withdraw from the Reagan-era Intermediate Range Nuclear Forces Treaty prompted Moscow, the pact's only other signatory, to do likewise. That removes restrictions that have kept the two nations from deploying ground-based nuclear-tipped missiles whose short flying times leave little margin for defending against them.
The U.S. is well beyond the range of such Russian missiles, but Europe most certainly is not. Still, NATO's Stoltenberg insists there will be no tit-for-tat with a Russia he, too, accuses of having cheated on the INF treaty.
"NATO has no intention of deploying land-based nuclear missiles in Europe," the NATO leader asserted at the joint meeting of Congress, "but NATO will always take the necessary steps to provide credible and effective deterrence." He did not say what those steps might be.
Meanwhile, Russia is sowing division in NATO by cozying up to some key members. The sale of its S-400 anti-aircraft system to Turkey does not necessarily violate NATO's rules — "It is a national issue what kinds of arms allies procure," says Stoltenberg — but it does cause doubts about where Ankara's allegiances truly lie.
Ditto for the Nord Stream 2 gas pipeline Germany is building with Russia. "It could turn Germany's economy literally into a captive of Russia," Pence warned NATO's foreign ministers.
In his 40-minute address to Congress, NATO Secretary General Stoltenberg made not one mention of China. It's a touchy subject for some NATO allies who have resisted U.S. entreaties — and ignored threatened U.S. trade sanctions — not to buy Chinese 5G technology upgrades.
China has also offered generous financing for infrastructure improvements in Europe as part of its One Belt, One Road initiative. And China's military ambitions could become a threat to NATO that were unimaginable when the alliance formed seven decades ago.
"Perhaps the greatest challenge NATO will face in the coming decades is how we must all adjust to the rise of the People's Republic of China," Pence declared this week, "and adjust we must."
All this has some NATO skeptics wondering how much longer the alliance hangs together.
"If NATO didn't exist, would we invent it?" says MIT political scientist Barry Posen. "I suspect not."
Others insist NATO will push on past its current troubles.
"As long as we're facing an aggressive Russia, and I think that means as long as Mr. Putin is in charge and maybe his successor after that, we're going to need NATO for its basic mission of collective defense and deterrence," says Alexander Vershbow, a former U.S. ambassador to Russia and deputy NATO secretary general. "So I think it has several more decades, at a minimum, in it — and maybe maybe even another 70 years."