Passed by a Democratic Congress during the Nixon administration, the Case Act required the president, acting through the office of the Secretary of State, to inform the Senate within 60 days of any executive agreement. No restriction was placed on presidential powers to make such agreements. However, the notification requirement put Congress in a position to be able to vote to cancel executive agreements, or to refuse to fund their implementation. As an example, in 1973 President Nixon signed an executive agreement with South Vietnam promising that the United States would "respond with full force" to North Vietnamese violations of the Paris Peace Accord, which had ended American military involvement in the Vietnamese War. However, when North Vietnam reinvaded South Vietnam in 1975, Congress refused presidential requests to appropriate funds for renewing American military aid to South Vietnam.