to the defeat. Adherents to this claim believed that South Vietnam could have been saved by another U.S. bombing campaign. The conflict between the executive and legislative branches of the American government, already severe before Operation Linebacker II in 1972, was only more exasperating during 1975, when a new campaign would probably only have provoked even more Congressional outrage. The third cause of the defeat was that the U.S. Congress simply wrote off and abandoned the Saigon government. Material shortages were indeed severe, and might explain, for example, why the Central Highlands had to be abandoned, but they do not explain the flight of senior South Vietnamese generals that led to complete collapse. Historian Arnold Isaacs, who was on the scene in South Vietnam at the time, believed that "The psychological damage of the aid cuts was almost certainly greater than the real ... Even with the full amounts requested by the executive, South Vietnam could not have done more than preserve the battlefield deadlock for another year, after which the whole exhausting debate would need to be replayed yet again – and in a presidential election year." Other plausible reasons for the rapidity of the defeat were the American policy of Vietnamization as a prescription for defeat. The rapid and accelerating withdrawal of U.S. forces that had begun in 1969 caught the South Vietnamese unprepared. The withdrawals were simply conducted faster than the South Vietnamese could or would improve. General Hinh believed that Vietnamization did not "provide the ARVN with enough time ... While the troop increases could be achieved rapidly, it was almost impossible to improve the quality and technical capabilities ...within the span of a few years. For seven years, the American military moulded South Vietnamese forces into a facsimile of itself, but ended up with a system that had all the liabilities of American military technology and few of its assets. The South Vietnamese military had greater problems than a reduction in American aid. President Thiệu was a disaster as commander-in-chief. During the two years before the offensive (when aid cuts were already occurring), neither he nor the General Staff made adjustments in strategy, doctrine, organization, or training to compensate for the inevitability of further aid reductions. Thiệu also deprived local commanders of any strategic or tactical flexibility in decision-making, which flowed downward from the presidential palace and those decisions contributed to the defeat. Added to