The so-called Quad, an informal inner circle of four powers — the United States, Britain, Germany and France — that has shaped Western decisions for decades, has ceased to function in the Trump era, insiders say.

Allied leaders learn of presidential decisions that affect their security and strategic interests via Twitter. There’s very little coordination, as became apparent last month when Trump ordered U.S. special forces out of northern Syria, where they had been operating alongside French and British commandos against Islamic State militants, without bothering to consulting NATO allies.

The messy pullback in Syria — which paved the way for NATO member Turkey to launch a cross-border offensive against Kurdish forces allied with the West, again without consultation — prompted French President Emmanuel Macron to diagnose the “brain death” of NATO and urge Europeans to build up autonomous defense capabilities. The U.S., he said, was turning its back on Europe.

Both of these NATOs — the well-oiled military machine and the dysfunctional political family — will be on parade when allied leaders hold a short working meeting on the outskirts of London on December 4 to mark the organization’s 70th anniversary.

To be sure, there’s plenty of NATO 1 business to discuss. The White House has said Trump wants to talk defense spending as always, as well as threats involving cyberspace, critical infrastructure, telecommunications and terrorism.

NATO Secretary-General Jens Stoltenberg, who has shrugged off talk of NATO being in crisis, wants the London meeting to showcase rising allied defense budgets — an additional $100 billion in European and Canadian defense spending — and progress toward meeting NATO’s readiness target of having 30 warships, 30 air squadrons and 30 army battalions ready to use within 30 days. European allies may also agree to take over more of NATO’s modest $1.65 billion annual running costs to reduce the U.S. share.

The trouble for the alliance is that statistics and declarations like those will mean little if NATO loses the political will to consult and act fast in a crisis. Swift decision making is crucial, especially in an era of fast-moving, ambiguous hybrid conflict involving undercover soldiers, sabotage, cyberattacks and disinformation.

In a command post exercise around a hybrid scenario two years ago, the North Atlantic Council dithered for five days over whether to send in the Very High Readiness Joint Task Force — NATO’s most rapidly mobilizable crisis response unit — until the alliance’s supreme commander in Europe had to report that it could no longer be deployed.

In a real crisis, would a conflict-averse Germany hold up decision-making to consult the Bundestag? Would Russia-friendly allies such as Hungary filibuster? Whose side would authoritarian Turkish President Tayyip Erdogan be on? And would NATO be left hanging on a single tweet from an unpredictable U.S. president?

The political alliance that is supposed to underpin the military one urgently needs repair. And yet in London, most allies and NATO officials are likely to focus on simply avoiding another bust-up with Trump that would delight Russian President Vladimir Putin. (The gathering has not been billed as a formal summit, to sidestep the need for a communiqué and avoid the train wreck of the last summit, in July 2018, when Trump berated allies for failing to meet spending targets).

German, Polish and British leaders have been quick to distance themselves from Macron’s criticism of NATO and insist the alliance remains central to European security. Although many privately share the French leader’s frustrations with Trump — and worry Washington’s attention is drifting away from Europe to China — most still prefer an uncertain American hegemon to a weaker French one with its own agenda.

Central European allies who live closest to Russia and count on the U.S. security guarantee, underpinned by nuclear weapons, were particularly irked by Macron’s words, as well as by his recent outreach to Putin.

But this being NATO, it’s not even certain that such sensitive issues will be thrashed out at all when the leaders meet. Germany proposed last week to NATO foreign ministers creating a panel of experts, possibly chaired by Stoltenberg himself, to strengthen the alliance’s political arm and improve coordination — a perfect way to kick the can down the road. The other foreign ministers said they’d think about it.

British Prime Minister Boris Johnson, hosting the gathering a week before a U.K. general election, wants to demonstrate that Britain will remain at the heart of transatlantic relations and European security after it leaves the European Union, and not become a “second-rate player” as outgoing European Council President Donald Tusk warned.

For all its faults, Macron’s “brain dead” barb was a necessary attempt to flush the issues of NATO 2 into the open and convince Europeans of the need to do more for themselves.

If the EU can leverage common funds and higher national defense spending to produce new capabilities, better infrastructure for military reinforcements, integrated cyber defenses and more efficient arms procurement, it will be a win-win for NATO and Europe.

The biggest risk to this plan is that Europe will once again over-promise and under deliver on building up its own military cooperation, while the U.S. under Trump continues to barrel ahead without consultation and leaves NATO in the dust.

In other words, the danger is that NATO 2 once again undermines NATO 1.