neutrality

Neutrality is both a body of international law and a foreign-policy posture by which a state refrains from taking part in hostilities between other states and maintains impartial relations with all belligerents. Its modern legal core is set out in the 1907 Hague Conventions V and XIII, which codify the inviolability of neutral territory, prohibit belligerents from moving troops or war materiel across it, and impose duties on neutrals to prevent their territory from being used for hostile acts.

Scholars and practitioners distinguish several variants:

• Permanent (or perpetual) neutrality, established by treaty or constitutional commitment, as with Switzerland after the 1815 Congress of Vienna and Austria under its 1955 State Treaty and constitutional law.
• Ad hoc neutrality, adopted with respect to a particular conflict.
• Armed neutrality, in which the neutral maintains substantial defensive forces to deter violation.
• Neutralism or non-alignment, a political stance of refusing bloc membership, distinct from legal neutrality; the Non-Aligned Movement founded in 1961 is the principal expression.

Neutrality carries reciprocal duties: abstention from supplying belligerents with arms or financing, impartial treatment of warships and aircraft, and internment of belligerent forces entering neutral territory. Belligerents, in turn, must respect neutral airspace, waters, and commerce, subject to recognised rules on contraband and blockade.

The UN Charter complicates classical neutrality. Article 2(5) and Chapter VII obligations to support Security Council enforcement measures can override neutral abstention, which is why several neutrals frame their status as compatible with UN sanctions and peacekeeping but not with collective defence alliances.

Neutrality has been tested repeatedly: violations of Belgian neutrality in 1914 and 1940, the contested wartime conduct of Sweden and Switzerland, and the post-2022 reassessments by Finland and Sweden, which led both to abandon non-alignment and join NATO.