So take it with a grain of salt...
http://en.wikipedia.org/wiki/Vietnam_war#Campaign_275In December 1974, the Democratic majority in Congress passed the Foreign Assistance Act of 1974, drastically reduced military funding to the South Vietnamese government and made unenforceable the peace terms negotiated by Nixon. Nixon, threatened with impeachment because of Watergate, had resigned his office. Gerald R. Ford, Nixon's vice-president stepped in to finish his term. The new president signed the law, complaining it was "clearly inadequate." By 1975, the South Vietnamese Army, with vast military hardware but shrinking morale, faced the well-organized, highly determined North Vietnamese. Within South Vietnam, there was increasing chaos. The withdrawal of the American military had compromised an economy that had thrived largely due to U.S. financial support and the presence of large numbers of U.S. troops. Along with the rest of the non-oil exporting world, South Vietnam suffered economically from the oil price shocks caused by the Arab oil embargo and a subsequent global economic downturn.