THE UN’s first peacekeeping mission, which started in 1948, was to keep a truce after the creation of Israel. Seven decades later, that mission continues, and the total number of peacekeeping operations worldwide has grown to 16, deploying more than 100,000 military personnel. Most are in Africa; the largest, in the Democratic Republic of Congo, involves 18,900 blue helmets.

The UN divvies up the cost of peacekeeping among its members using a complicated formula that includes economic heft. Later this year China will double its paymemts to more than 10% of the global total, overtaking Japan as the second largest contributor. America shells out more than a quarter, and together the top ten countries account for four-fifths. But when it comes to manpower, the pattern is very different. Since 18 American soldiers died when a helicopter was shot down in Somalia in 1993, the United States has almost stopped sending troops. It now has only 74 military personnel involved in peacekeeping, only half of them soldiers.

Altogether, the ten biggest budget contributors supply only 6% of peacekeepers. China is the only country to feature on both top ten lists. But it is African and Asian countries that provide the lion’s share of troops. The UN pays countries $1,330 a month per soldier, meaning that peacekeeping can be lucrative for poor nations. Tiny Rwanda contributes 6,146 military personnel and pays just $16,500 to the budget annually, about as much as it receives for supplying one soldier.