By 1973, the goal of fashioning a South Korean-like, noncommunist entity in Indochina was supposedly obtained and the war over. The Paris peace agreements recognized two autonomous Vietnamese states. Almost all American prisoners were returned. The last few U.S. ground troops came home.

If the communist North, and its Soviet and Chinese patrons, saw 1973 as a breather rather than a peace, American officials at least promised the South material support and air cover if the communists reinvaded.

They did just that in spring 1975, barreling down Highway 1 with conventional Soviet tanks. Americans apparently did not want another quarter-century commitment to a second Demilitarized Zone to ward off a perpetual communist threat from the north. By 1974, a series of congressional acts radically cut funding of U.S. military support of South Vietnam. The Saigon government abruptly collapsed in April 1975.

There are lessons here. When the United States has stayed on after fighting dictatorial enemies - admittedly for decades in Italy, Germany, Japan, Korea and the Balkans - progress toward democracy and prosperity ensued. Disengagement from unresolved messy problems - whether from Europe after World War I, Vietnam in 1973, Beirut after the Marine barracks bombings, Afghanistan after the Soviet defeat, or Iraq in 1991 - only left murderous chaos or the "peace" of dictators.

Congress proceeded to snatch defeat from the jaws of victory. Since our troops were out of Vietnam, Congress initiated a total retreat from our commitments to the South Vietnamese people. First, it destroyed our ability to enforce the peace agreement, through legislation prohibiting the use of American military power in Indochina. Then it undercut South Vietnam's ability to defend itself, by drastically reducing our military aid. Within two years the balance of power swung decisively in Hanoi's favor. When the North Vietnamese Army was poised to launch its final offensive, South Vietnam's army was in its weakest condition in over five years, reeling from the effects of congressional budget cuts that had strapped it with severe fuel and ammunition shortages.

1. The Government of the United States of America will contribute to postwar reconstruction in North Vietnam without any political conditions.

2. Preliminary United States studies indicate that the appropriate programs for the United States contribution to postwar reconstruction will fall in the range of $3.25 billion of grant aid over five years. ...

The antiwar sentiment was largely limited to Indochina. While some media critics irresponsibly charged that I called an alert of United States forces during the Yom Kippur War in October 1973 solely to divert attention from Watergate, there was overwhelming support in the Congress for the massive airlift and other military actions I took to save Israel. But Vietnam was different. Without Watergate, we would have faced the same opposition to our use of military power to enforce an agreement that would bring peace to Vietnam.

I was caught off-guard by the intensity of this backlash. ...

We could not find strong support for our policy in any quarter. ...

Hawks supported the American war effort initially. But its length had taken its toll. As the war became more unpopular, they tired of the struggle and kept a low profile politically. I could still count on their votes during the war, and most remained true to our cause afterward. But none was willing to lead the charge on Capitol Hill.

I was shocked by the irresponsibility of the antiwar majority in Congress.
...

I could understand their desire to put the Vietnam War behind us. But I could not understand why they seemed so determined to see South Vietnam conquered by North Vietnam. Whatever their intentions, that was the effect of their actions.

South Vietnam's crumbling economy eroded army morale, which had been surprisingly high until then. A survey conducted during the summer of 1974 by the U.S. mission in Saigon found that more than 90 percent of the soldiers were not receiving enough in wages and allowances to sustain their families. Inflation was only one cause, however. Corruption was now exceeding all bounds as commanders robbed payrolls and embezzled other funds. Quartermaster units often insisted on bribes in exchange for delivering rice and other supplies to troops, and even demanded cash to furnish the fighting men with ammunition, gasoline, and spare parts. Officers frequently raised the money by squeezing local villagers, whose support they alienated in the process, and many traded with the Communists privately. The American report cautioned that the "deterioration" had to be halted "if the South Vietnamese military is to be considered a viable force." Ambassador Martin dismissed the warning with a tired cliche: "a little corruption oils the machinery." There was nothing he could do, in any case. Thieu's wife and cronies and their wives, indifferent to the danger, were reaping fortunes in real estate and other deals, and they set the code of misconduct for the entire officialdom. Or as an old Vietnamese adage put it: "A house leaks from the roof."

[US] Ambassador [to South Vietnam Graham] Martin and others were to assert that the cuts in U.S. assistance had prevented the South Vietnamese from resisting the Communists effectively, but a Pentagon study later noted that only about two fifths of the $700 million allocated actually reached Vietnam; the rest was committed to equipment that awaited shipment or had not yet been spent.

Aside from the venality and professional incompetence of much of its senior officer corps, the [South Vietnamese] RVNAF [armed forces] could hardly be expected to shoulder the immense technical and logistical demands imposed upon it by the American style of warfare it was trained and equipped to wage. Though by 1975 the war had been thoroughly Vietnamized, the RVNAF had been transformed into a military force incapable of sustaining itself in combat, notwithstanding the mountains of American military equipment and ammunition that were transferred to the RVNAF between 1973 and 1975. Vietnamization, wrote a young Sen. Sam Nunn on the eve of Hanoi's final offensive, "has resulted in the Americanization of the Vietnamese" via "the dumping of massive amounts of military equipment and supplies on a South Vietnamese force that was unprepared and incapable of coping with the logistics and maintenance requirements related to that equipment.

"There was no more reason to have confidence in U.S. air power than in Vietnamization. Even if Congress had been prepared to approve a post-Paris U.S. reentry into the Vietnam War - which it manifestly was not - it is far from clear that any amount of U.S. bombing, absent a return of U.S. ground forces, could have thwarted Hanoi's ultimate victory in the South. At no time during the war had bombing succeeded either in shutting off the flow of supplies down the Ho Chi Minh Trail or in compelling Hanoi to negotiate a settlement on terms that precluded reasonable chances for Vietnam's subsequent forcible reunification. Linebacker II, the so-called "Christmas bombing" of targets in and around Hanoi in 1972, was launched in part to persuade Hanoi to accept settlement terms additional to those which it had already accepted the preceding October but on which the United States, because of bitter South Vietnamese objections, sought to renege.

The United States abandoned its cause in Indochina because it was strategically, politically, fiscally, and morally exhausted. Never prepared (nor should it have been) to make anything remotely approaching the proportional sacrifices in blood and treasure in Indochina that its communist enemy was willing to—and did—make, and being a democracy in which official policy fundamentally hostile to the electorates wishes could not be indefinitely pursued, the United States withdrew from Vietnam because it had no other choice.

It is difficult to avoid the conclusion that the United States lacked any strtegically decisive and morally acceptable war-winning military options in the Vietnam War. Options considered - and not considered - were either peripheral or, if potent and at least theoretically decisive, unacceptable. The military's vain push for ground war options in Laos and Cambodia and expanded air war options against North Vietnam was a push, in effect, for an extension of the military stalemate in Indochina at a higher and more costly level of violence, though these rebuffed options continue to serve the cause of those who believe that the Vietnam War was a case of American self-defeat.