Media attention focused on the death of the 2,000th American soldier in Iraq last week. But that grim event alone probably won’t prove a tipping point in public opposition to the war. After 30 months of fighting, most Americans have already turned against the war. Polls find that 54 per cent believe the US made a mistake in sending troops to Iraq, up from 24 per cent in March 2003. It’s not the specific number of casualties so much as the steady drumbeat of carnage that causes people to lose their stomach for war. The truth is that even dramatic events do not necessarily greatly affect support for the cause.

Compare Iraq to Vietnam. Although the 1968 Tet offensive did cause people to worry that the war was not going well, support did not plummet. It simply continued to drift downward. In Iraq, support bumped up a bit when Saddam Hussein was captured and when polls were held, and it slumped at the time of the Abu Ghraib disclosures. But in each case, it soon returned to its previous course.

What’s unprecedented about this war is how fast support is eroding. Casualty tolerance in Iraq is much lower than it was in Vietnam. Support levels for this war when 2,000 American soldiers have been killed are about the same as they were in the Vietnam War when well over 20,000 perished. This suggests that public places a much lower value on the stakes in Iraq than it did in Vietnam.

Support for the war rose briefly at the time of London bombings in the summer. But the attacks also tended to undercut the Bush administration’s argument that the terrorists were so busy in Iraq that they couldn’t operate elsewhere. The Bush administration hopes to reverse the downward trend with upbeat speech-making that claims progress in Iraq. The same approach was used in the Vietnam but with little success. The problem is that people who always believed the war wasn’t “worth it” won’t be converted, and those who have become disenchanted are not easily won back. More than 80 per cent of war opponents say they “strongly” object, and more than half say they are angry about the war, not merely dissatisfied. The Democrats have become disaffected and there are signs lately that support even from the Republicans is fading.

But polls are not referendums. Eroding public support cannot keep the administration from continuing to prosecute the war any more than discontent did in Vietnam, unless it is expressed in congressional action. Moreover, though a decline in American casualty rates is unlikely to boost support, it may, as in Vietnam, cause the public to pay less attention to the conflict. However, withdrawal from Vietnam was much more difficult politically for congressional opponents than it would be in the case of Iraq. North Vietnam held about 500 US prisoner, and leaving Vietnam without getting those prisoners back was a political non starter. There is no comparable POW problem in Iraq but that doesn’t mean ending the war will be easy. — The Christian Science Monitor