BEIJING -- With Jamaica's currency in free fall, unemployment soaring and banks heavily exposed to government debt, the Caribbean island's diplomats went into crisis mode earlier this year. They traveled to all corners of the world to seek help.

Jamaica's traditional allies, the United States and Britain, were preoccupied with their own financial problems, but a new friend jumped at the opportunity to come to the rescue: China.

When contracts for loan packages totaling $138 million were signed between the two countries in March, China became Jamaica's biggest financial partner. Headlines in Jamaica's leading newspapers, which only a year ago were filled with concern about China's growing influence in the region, gushed about its generosity.

"The loan couldn't...