How did the Hague Conventions of 1899 and 1907 limit the conduct of war?

The Hague Conventions of 1899 and 1907 were landmark international treaties that established essential rules governing the conduct of war on land and at sea, marking a significant shift in how states exercised their sovereignty during conflicts.1

These conventions limited the conduct of war through several key mechanisms:

• Restrictions on Methods and Means: Article 22 of the 1907 regulations established that the right of belligerents to injure the enemy is not unlimited. The treaties prohibited treacherous conduct, the killing of those who have surrendered, and the use of weapons calculated to cause unnecessary suffering.2
• Specific Prohibitions: The 1899 conference adopted declarations banning the use of asphyxiating gases, expanding bullets, and the discharge of explosives from balloons.3
• Protection of Neutrals: The 1907 conventions mandated that the territory of neutral powers is inviolable and established duties for both neutral states and belligerents to prevent the expansion of conflict into neutral zones.4
• Pacific Dispute Resolution: The 1899 convention established the Permanent Court of Arbitration to encourage the peaceful settlement of international disputes.3

By codifying these customs, the Hague Conventions helped transition international law away from the view that war was an unrestricted exercise of sovereign power.15