Paul Taylor, a contributing editor at POLITICO, writes the Europe At Large column.

PARIS — The EU now has a “geopolitical European Commission,” a shared determination to take more responsibility for its own security, an ambitious plan to develop European defense cooperation and a nascent fund for military research and development. What could possibly go wrong?

Lots. Defense is at the heart of national sovereignty, and even the most enthusiastic national governments such as France are reluctant to pool their forces, equipment or industries, while Central European countries see NATO and the United States as their only reliable guardians.

Building a European defense union was always going to be a long haul, but there are at least four ways in which the current drive for greater EU ambition could lead to disillusionment — or even a military debacle.

Butter before guns

The most immediate risk of a let-down lurks in negotiations on the long-term EU budget. The Commission has proposed a €13 billion fund to co-finance cross-border military research and development projects.

This so-called European Defense Fund would be the first use of the EU’s community budget for defense — and to underline the priority, Brussels has created a directorate general for defense industries and space under European Commissioner for the Internal Market Thierry Breton.

Aimed at encouraging national governments to procure equipment jointly and avoid costly duplication (and dependence on Washington), the defense fund offers an incentive for companies and research centers to collaborate since each project must involve at least three entities in three EU countries.

That will only work if there’s enough money to be used as an incentive — something already in doubt as the haggling over the EU’s next seven-year budget continues.

Under pressure from net contributors to plug the financial hole left by the U.K.’s departure, the Finnish EU presidency proposed in December slashing the allocation for 2021-2027 by almost half. It also suggested halving a military mobility fund to upgrade roads, bridges, railways, airfields and ports to facilitate rapid reinforcement in a crisis.

EU budget battles usually end up with legacy spending programs being preserved due to the power of the farm and regional cohesion lobbies, while innovative programs wither in the final nights of haggling. Butter before guns is the likely outcome this time too.

After proclaiming the goal of “strategic autonomy” and setting out to build a defense industrial and technological base to match its geopolitical ambitions, the EU may be about to give birth to a mouse. Cue scorn from Washington, sniggers in Moscow and an inscrutable smile in Beijing.

Dither and muddle

Another ominous indicator of the EU’s credibility gap in defense is the inability of national governments to agree on how to tackle recent crises in Europe’s backyard and the reluctance to take strong action.

Since the start of the year, foreign ministers have dithered over what military role, if any, the EU should play in efforts to end the civil war in Libya that poses security and migration threats to Europe.

They have imposed only symbolic sanctions on two individuals over Turkey’s gunboat-backed drilling for gas in the exclusive economic zone of Cyprus, an EU member. And they have struggled to take a joint position on U.S. President Donald Trump’s one-sided plan for an Israeli-Palestinian peace settlement that tore up decades of international resolutions to Israel’s advantage.

This makes the EU look impotent and irrelevant in its own neighborhood while other players such as Russia and Turkey create facts on the ground militarily and diplomatically.

The bloc’s new foreign policy chief, Josep Borrell, has voiced ambitions to send an EU military mission to implement a cease-fire in Libya and enforce a widely flouted U.N. arms embargo in the North African state. But with France favoring rebel General Khalifa Haftar while Italy backs the U.N.-recognized Tripoli government under Fayez al-Sarraj, joint EU action looks remote.

“There is no secret that on this question, we Europeans, we have been suffering from internal divisions and we have not been united enough ... to present a coherent position that gives us strength,” Borrell said in Berlin.

Fair-weather missions

With the EU hamstrung by complex decision-making processes that require unanimity, coalitions of willing European countries will likely remain the preferred route for all but the least risky interventions.

The danger, however, is that such coalitions embark on over-optimistic or underpowered missions that run into trouble and end up having to turn to the U.S. for support or to rescue European forces.

That is what happened in Bosnia in the 1990s, when U.K. and French-led U.N. peacekeepers were hapless spectators or targets for Bosnian Serb forces until U.S. President Bill Clinton led a NATO air campaign and forced a political settlement, to the Europeans’ embarrassment.

A quarter of a century later, France is trying to build European coalitions to help uphold freedom of navigation in the Strait of Hormuz, the gateway to the Gulf, following attacks on oil tankers blamed on Iran’s Revolutionary Guards, and to deploy special forces against jihadist insurgents in the Sahel region of Africa.

The U.K. may no longer have its foot on the brakes of EU defense integration, but Brexit could nonetheless undermine Europe’s military ambitions.

Paris is struggling to secure active contributions for either initiative. The Netherlands and Denmark have committed a warship each to the Gulf mission, while Germany, Belgium, Italy, Greece and Portugal have pledged political support. Estonia and the Czech Republic are the only partners to have offered special forces so far to join Operation Takuba in the Sahel.

The European Maritime Awareness in the Strait of Hormuz (EMASoH) mission, launched in January and based in Abu Dhabi, aims “to foster de-escalation and to complement vital diplomatic efforts” for regional stability and dialogue. Iran may see things differently. What happens if Revolutionary Guard speedboats challenge a European patrol boat?

The French say EMASoH is independent of but complementary to a U.S.-created international maritime security force in the Gulf, which Britain joined after Iran seized a U.K.-flagged tanker last year. What happens if things get kinetic? Might Paris have to call Uncle Sam to the rescue despite disagreement with Washington’s strategy of “maximum pressure” against Tehran?

Shutting Britain out

The U.K. may no longer have its foot on the brakes of EU defense integration, but Brexit could nonetheless undermine Europe’s military ambitions.

Britain accounted for almost 25 percent of EU defense spending and the country was, alongside France, the bloc’s most active nuclear-armed military power with a permanent U.N. Security Council seat. It also has the joint largest defense industry and strong intelligence services.

While Prime Minister Boris Johnson has vowed that the U.K. will remain committed to European security through NATO and bilateral cooperation — most notably with France — London looks unlikely to join EU-led military operations, where it would have less say than member countries.

Moreover, the cross-Channel integration of the European defense industry could be thrown into reverse if U.K.-based manufacturers are shut out of European Defense Fund projects and multinational defense companies are handicapped by border checks on goods and staff.

European defense could be a collateral casualty of a U.K.-EU trade war. France has proposed giving Britain a seat in a yet-to-be-created European Security Council to discuss common strategic challenges. But it’s hard to imagine British and European forces embarking on joint missions or industrial projects if London and Brussels are at daggers drawn over tariffs, quotas and regulatory alignment.

An acrimonious no-deal Brexit could end up definitively spiking Europe’s guns.