The cables, a huge sampling of the daily traffic between the State Department and some 270 embassies and consulates, amount to a secret chronicle of the United States’ relations with the world in an age of war and terrorism.

Bargaining to empty the Guantánamo Bay prison: When American diplomats pressed other countries to resettle detainees, they became reluctant players in a State Department version of “Let’s Make a Deal.” Slovenia was told to take a prisoner if it wanted to meet with President Obama, while the island nation of Kiribati was offered incentives worth millions of dollars to take in Chinese Muslim detainees, cables from diplomats recounted. The Americans, meanwhile, suggested that accepting more prisoners would be “a low-cost way for Belgium to attain prominence in Europe.” 

Suspicions of corruption in the Afghan government: When Afghanistan’s vice president visited the United Arab Emirates last year, local authorities working with the Drug Enforcement Administration discovered that he was carrying $52 million in cash. With wry understatement, a cable from the American Embassy in Kabul called the money “a significant amount” that the official, Ahmed Zia Massoud, “was ultimately allowed to keep without revealing the money’s origin or destination.” (Mr. Massoud denies taking any money out of Afghanistan.) 

Clashes with Europe over human rights: American officials sharply warned Germany in 2007 not to enforce arrest warrants for Central Intelligence Agency officers involved in a bungled operation in which an innocent German citizen with the same name as a suspected militant was mistakenly kidnapped and held for months in Afghanistan. A senior American diplomat told a German official “that our intention was not to threaten Germany, but rather to urge that the German government weigh carefully at every step of the way the implications for relations with the U.S.”