Europe's Self-Defense Paradox: Can the Continent Protect Itself Under Its Own Rules?

Situation Assessment

Israeli Ambassador Ron Prosor, in a guest column for the Frankfurter Allgemeine Zeitung, argued that President Steinmeier's reading of international law would "prevent not just Israel's right but, in an emergency, also Germany's ability for self-defense." His framing went further: "Under the umbrella of international law, they can threaten our countries without ever facing consequences." The argument is directed at Steinmeier, but the target is broader. European defense rests on overlapping legal frameworks that have never been reconciled, and Prosor's challenge exposes the fault line.

The Legal Architecture

Four frameworks govern how European states may use force in self-defense. They overlap, and in critical areas, they contradict each other.

UN Charter Article 51 states that "nothing shall impair the inherent right of individual or collective self-defence if an armed attack occurs." The operative word is "occurs." A restrictive reading permits force only after an attack has begun. A permissive reading extends the right to imminent threats. The International Court of Justice has never definitively settled which reading prevails.

In Nicaragua v. United States (1986), the ICJ affirmed the customary right of self-defense but set a high threshold for what qualifies as an armed attack. In Oil Platforms (2003), the court ruled that the United States had failed to demonstrate that Iran's actions constituted armed attacks justifying a self-defense response. Both rulings narrowed the practical scope of Article 51 without resolving the anticipatory question.

NATO Article 5 provides collective defense: an armed attack against one member is an attack against all. It has been invoked exactly once, on 12 September 2001, one day after the attacks on New York and Washington. The threshold mirrors Article 51: an armed attack must occur. NATO does not authorize preemptive collective action.

EU Article 42.7 TEU establishes a mutual defense obligation among EU member states. It lacks NATO's integrated command structure and has no standing military mechanism. France invoked it on 17 November 2015, four days after the Paris attacks, rather than invoking NATO Article 5. That choice was deliberate. This suggests Paris preferred a European solidarity framework over the Atlantic alliance for that particular crisis, though France has not publicly confirmed the strategic reasoning.

The Caroline doctrine, dating to an 1837 incident on the Niagara River, permits preemptive self-defense where the threat is, in Daniel Webster's formulation, "instant, overwhelming, and leaving no choice of means, and no moment for deliberation." The doctrine is cited in international law scholarship and was referenced in the Nuremberg Tribunal proceedings. The ICJ has never formally adopted it as binding law.

The result is a layered architecture in which each framework addresses a slightly different situation, and none covers the full spectrum of modern threats.

What European States Actually Did

When European states deployed military force, they cited different legal bases each time.

For Libya in 2011, UN Security Council Resolution 1973 authorized "all necessary measures" to protect civilians. France and the United Kingdom led the air campaign under this mandate. No self-defense claim was required or made.

For Mali in 2013, France launched Operation Serval citing collective self-defense at Mali's invitation, supplemented by UNSC Resolution 2085. France did not invoke EU Article 42.7 despite the operation's scale.

The Syria campaign from 2014 onward produced the widest legal divergence. The US-led coalition cited collective self-defense of Iraq under Article 51. The United Kingdom cited individual self-defense for a 2015 drone strike on a British citizen in Raqqa. France cited self-defense after the November 2015 Paris attacks. Germany, deploying reconnaissance aircraft and a frigate, cited collective self-defense of France under EU Article 42.7.

One operation, four participating European states, at least three distinct legal justifications.

France's approach stands apart from its allies for a structural reason. The force de frappe, France's independent nuclear deterrent, exists precisely because Paris does not fully delegate defense decisions to NATO. The doctrine assumes France may need to act alone, without alliance consensus and without waiting for a legal framework to align. This is one European answer to the self-defense paradox: maintain an independent capacity and decide the legal justification afterward.

The Anticipatory Self-Defense Gap

The sharpest edge of the paradox sits here: the law does not clearly permit what strategic reality may demand.

The ICJ has never endorsed anticipatory self-defense in a binding ruling. In its 2004 Advisory Opinion on the Israeli separation wall, the court rejected Israel's Article 51 claim on the grounds that the threat did not originate from another state. The ruling did not address whether anticipatory self-defense is permissible when the threat does come from a state actor.

The 2004 UN High-Level Panel on Threats, Challenges and Change acknowledged that an "imminent threat" could justify preemptive force, but the panel's report carries no binding legal authority. States cite it when convenient and ignore it otherwise.

Domestic constraints compound the gap. Germany's Parlamentsvorbehalt requires Bundestag approval for any armed deployment of the Bundeswehr beyond routine NATO obligations. This adds days or weeks to any decision-making timeline, making rapid preemptive action structurally difficult regardless of what international law might permit. The United Kingdom's convention of seeking parliamentary approval before military action, though not legally binding, creates a similar practical delay.

What remains is a legal grey zone. European states possess significant military capabilities but lack a settled legal framework for using them against threats that have not yet materialized into armed attacks.

International Law as Weapon

The instrumentalization of legal frameworks for strategic advantage has a name. Charles Dunlap, then a US Air Force Colonel, coined the term "lawfare" in a 2001 paper at Harvard's Carr Center for Human Rights Policy, defining it as "the use of law as a weapon of war."

The concept has since played out across multiple conflicts.

Russia invoked "self-defense of Russian speakers" and the responsibility to protect doctrine to justify military operations in Georgia in 2008 and in Ukraine in 2014 and 2022. The ICJ, in its provisional measures order on Ukraine v. Russia (2022), ordered Russia to immediately suspend military operations, implicitly rejecting these legal justifications.

China cites the UN Convention on the Law of the Sea and "historic rights" simultaneously to assert sovereignty over the South China Sea, despite the Permanent Court of Arbitration ruling against its claims in Philippines v. China (2016). Beijing has refused to recognize the ruling.

Iran frames its nuclear program as peaceful use under Article IV of the Non-Proliferation Treaty while accusing states that threaten military action of violating the prohibition of force under UN Charter Article 2(4).

Each actor uses the same body of international law to reach opposing conclusions. The framework designed to constrain the use of force functions, in practice, as an additional arena of competition.

This context reframes Prosor's argument. His claim that Steinmeier's interpretation benefits Moscow and Tehran is itself a form of lawfare: using the opponent's legal framework against him to argue it produces absurd consequences. Whether the argument is valid depends on which reading of Article 51 one accepts, and that question, as established, remains unsettled.

What Remains Unclear

Several questions sit at the boundary of current international law, unresolved.

No European state has published a comprehensive doctrine specifying when anticipatory self-defense is legally permissible and under which framework. The EU Strategic Compass, adopted in 2022, proposed a 5,000-strong Rapid Deployment Capacity but did not address the legal basis for its use in scenarios short of an armed attack. NATO's 2022 Strategic Concept designated Russia as "the most significant and direct threat to Allies' security" but did not expand the Article 5 trigger beyond an armed attack.

Whether cyber attacks or sustained hybrid warfare campaigns constitute "armed attacks" under Article 51 remains an open question. The Tallinn Manual, produced by NATO's Cooperative Cyber Defence Centre of Excellence, offers scholarly guidance but no binding legal standard.

European states have, for decades, navigated this incoherence by improvising legal justifications after each crisis. The legal architecture is not a system designed for the threats it now faces. It is a patchwork, assembled across different eras and for different purposes, that European capitals have chosen not to consolidate.

Prosor's challenge to Steinmeier, whatever its diplomatic motivations, points at a real structural gap. Whether Europe can defend itself is not primarily a question of military capability. It is a question of whether its legal framework permits the defense its capabilities could provide.