From the Overview: "Though only about three times the size of Washington, DC, and with a population of 5.5 million, the city-state of Singapore punches far above its weight in both economic and diplomatic influence. Its stable government, strong economic performance, educated citizenry, and strategic position along key shipping lanes make it a major player in regional affairs. For the United States, Singapore is a crucial partner in trade and security cooperation, as the Obama Administration executes its rebalance to Asia strategy. Singapore's value has only grown as the Administration has given special emphasis to the Association of Southeast Asian Nations (ASEAN) as a platform for multilateral engagement. Singapore's heavy dependence on international trade makes maintaining regional stability one of its foremost priorities. As a result, the nation is a firm supporter of both U.S. trade policy and the U.S. security role in Asia. However, the country also maintains close relations with China."
CRS Report for Congress, R44127
Congressional Research Service: https://crsreports.congress.gov/