Presidency of Ronald Reagan to forestall the possibility of an agreement between the United States and the Soviet Union. Nonetheless, both Gorbachev and Reagan agreed to continue arms control negotiations at the October 1986 Reykjavík Summit. At the summit, Gorbachev and Reagan closed in on an agreement to greatly reduce or eliminate the nuclear stockpiles of both the U.S. and the Soviet Union over a ten-year period, but the deal collapsed due to disagreements regarding SDI development. Reagan attacked Gorbachev in a 1987 speech delivered in West Berlin, but negotiations continued. Gorbachev and Reagan broke the impasse by agreeing to negotiate separate treaties on
Nancy Reagan failed to include some $3 million worth of fashion items between 1983 and 1988 on their tax returns; they were billed for a large amount of back taxes and interest, which was subsequently paid. After President Reagan revealed that he had been diagnosed with Alzheimer's disease in 1994, she made herself his primary caregiver, and became actively involved with the National Alzheimer's Association and its affiliate, the Ronald and Nancy Reagan Research Institute in Chicago, Illinois. In April 1997, Nancy Reagan joined President Bill Clinton and former Presidents Ford and Bush in signing the Summit Declaration of Commitment in advocating