Paul H. Nitze, a senior arms control adviser in the Reagan administration who served in various national security roles under eight presidents, died late Tuesday at 97. Reports of his death were confirmed by the Navy Department, which Nitze once headed. His long career, which began with success on Wall Street as a young investment banker, was capped last April in Bath, Maine, where Nitze witnessed from a wheelchair the christening of a warship bearing his name. The Johns Hopkins School of Advanced International Studies in Washington was founded in 1943 by Nitze and the late former Secretary of State Christian Herter.Nitze, a conservative Democrat, was a natural fit for Ronald Reagan's administration because they both opposed President Jimmy Carter's 1979 Strategic Arms Limitation Treaty with the Soviet Union. Nitze headed the policy planning office of the State Department in the Truman administration. He took charge of negotiating reductions in intermediate- range missiles with the Soviet Union in 1981 for Reagan, who had changed directions to support arms control accords. He is survived by his wife Elisabeth Scott Porter; his sons, Peter Nitze and William Nitze, and their wives, Susan and Ann; his daughters, Heidi Nitze and Anina Moriarity and her husband, Marshall; his stepdaughter, Erin Porter and her husband, Jesse Fisher; eleven grandchildren, seven great-grandchildren, seven great-grandchildren and three step-grandchildren.