Japan-U.S. relations during the second four-year term of U.S. President Barack Obama will depend much on the stability of political leadership in Tokyo, a leading American expert on Japan said during a recent seminar in Tokyo.

Obama's re-election and the upcoming general election in Japan will make 2013 a crucial year to resolve the continuing deadlock over relocation of the U.S. Marine Corps Air Station Futenma in Okinawa, said Kent Calder, director of the Edwin O. Reischauer Center for East Asian Studies at Johns Hopkins University. Some modifications to the 2006 agreement between the two governments may be needed to make the plan "politically feasible," he said.

Calder was speaking at an event organized by the Keizai Koho Center on Nov. 14 to discuss the outcome of the U.S. presidential election and its policy implications, including relations with Japan.