Nov. 20, 2006 at 5:21PM

President Bush is changing course on Iraq just as President Johnson did on Vietnam after the 1968 Tet offensive. But the situation facing U.S. policymakers now in Iraq is vastly worse than anything their predecessors faced after Tet.
As we noted in our previous UPI Eye on Iraq column, the Tet offensive was in military terms a catastrophic defeat for the Viet Cong from which they never recovered as an effective fighting force. It was an overwhelming victory for the U.S. Army and for the Army of the Republic of South Vietnam. It was the political and strategic impact of Tet on American public opinion, key American media figures like CBS news anchor Walter Cronkite and on President Johnson and his policymakers that proved lasting.
Even then, the war was not fated to be lost. Following the change of U.S. policy on Vietnam after Tet under Defense Secretary Clark Clifford and Gen. Creighton Abrams -- the much loved and respected successor to the widely despised Gen. William Westmoreland as U.S. commander in South Vietnam -- U.S. and South Vietnamese operations became markedly more effective. This continued to be the case under President Richard Nixon and his defense secretary, Melvin Laird.
However, the political crippling of the U.S. presidency in the Watergate scandal left South Vietnam isolated and defenseless against a massive, North Vietnamese conventional military conquest that was lavishly supported by the Soviet Union. But even after Tet and the change of course under President Johnson, it was still far from inevitable that South Vietnam would fall to the communists.
However, where Tet was a striking U.S. victory, Rumsfeld's last great strategic offensive in Iraq -- the drive by the U.S. armed forces to try and destroy the power of the paramilitary militias that control most of Baghdad, was a huge strategic failure.
There was no failure in the skills and courage of the U.S. forces involved in the operation, and the casualties they suffered, while distressing, were vastly less than U.S. casualties during Tet, or any other period of intense military conflict in South Vietnam. Nor did the operations fail because of any tactical shortcoming by U.S. commanders on the ground in Baghdad. They failed because they could not succeed. They failed because Baghdad 2006 was so strikingly different from Tet 1968.
The Tet offensive was waged by a single guerrilla organization, the Viet Cong, which was the only alternative source of political authority and organization to the existing Saigon government of President Nguyen Van Thieu in South Vietnam. President Thieu's administration was a longstanding government that provided effective security and basic services through much of the country. The decimation of the Viet Cong elite guerrilla warfare cadres in Tet massively degraded the communist insurrection and the Saigon government therefore grew in military and political strength in the years immediately following Tet.
By contrast, the military offensive in Baghdad in the late summer and early fall of 2006 was launched by U.S. forces against not one but several militias including Shiite ones that had very close ties to the democratically elected, but exceptionally weak and ineffectual government of Iraq led by Prime Minister Nouri al-Maliki.
Where Viet Cong forces were trapped and wiped out during Tet, major Shiite militia paramilitary formations were not even significantly degraded in Baghdad. Where Tet boosted the military power and political credibility of the Thieu government among the South Vietnamese people, the success of the militias in defying the U.S. forces further undermined the Maliki government.
Where the Thieu government, although established by military officers and unelected, was an effective government before Tet, the Maliki government, although based on a democratically elected parliament, had shown itself in the half year before the Baghdad fighting unable to guarantee security and basic services in much of Iraq. That was especially the case in the government's own capital, except where it depended upon the support and approval of the Shiite militias.
The Maliki government is therefore far weaker after the 2006 fighting in Baghdad than the Thieu government was after Tet 1968. U.S. ground forces in South Vietnam after were supplied across the ocean by air and their lines of communications where never seriously threatened. U.S. ground forces in Iraq remained in 2006 precariously dependent on the land route to Baghdad from Kuwait and Basra that the Shiite militias controlling most of southern Iraq could interdict at any time.
Ties between the Thieu government and the U.S. government and military grew far closer after Tet. Ties between the Maliki government and the U.S. government and military grew dangerously strained after the fighting in Baghdad. After Tet, the Viet Cong was weaker. After Baghdad, the Sunni insurgents were stronger.
After Tet, the U.S. forces in Vietnam still could concentrate on the Viet Cong and their North Vietnamese army allies. Increasingly, even major guerrilla operations were fought by North Vietnamese officered, and partially manned, forces rather than purely indigenous South Vietnamese Viet Cong ones. The Army of the Republic of South Vietnam became more credible after Tet. The new Iraqi army, heavily penetrated by Shiite militias, became far more unreliable as an ally to the U.S. forces in Iraq after Baghdad.
U.S. policymakers and public opinion arguably became too pessimistic after Tet. They probably remain far too optimistic after Baghdad.