Democrats have warned that Ms. Palin, a first-term governor, is woefully inexperienced and is not qualified to serve a “heartbeat” away from the presidency. In her first interview for over two weeks, the 44-year-old mother of five struggled, when asked her views of the Bush doctrine, which states the United States will mount a preemptive strike against a looming threat if it deems itself at risk.

Labor’s policy on Afghanistan has consistently been that Australia’s presence there, rather than Iraq, represents our commitment to fighting al-Qaeda and the Taliban at “the coalface”. But the promises Labor made while in Opposition are forcing our troops into a long fight that will test even the might of the United States.

General Petraeus, the principal architect of the successful 2007-08 surge of US troops that restored security across Baghdad, says the signs of positive change are everywhere. “We have gone from a situation where 14-15 months ago there were 180 attacks a day in Iraq. Now there are on average about 25 attacks a day,” he said.

The economy — not national security — is shaping up as the far greater concern this year, and the poll shows that Senator Obama, the presumptive Democratic nominee, was trusted more by voters to handle this issue. Sixty-five percent of those surveyed said they were confident that Mr. Obama would make the right decisions on the economy, compared with 54 percent who expressed confidence that Senator McCain, the presumptive Republican nominee, would.

The shift in military power and popular support in Baghdad, if it holds, would solidify a transfer of power from the anti-American cleric Moktada al-Sadr Sadr, who had lorded his once broad political support over the government, to Prime Minister Nuri al-Maliki, who is increasingly seen as a true national leader.

For months Senator John McCain, the presumptive Republican nominee, has railed against setting timetables for withdrawing from Iraq, and has criticized Senator Barack Obama, his Democratic rival, for suggesting one. But in recent days the debate has shifted as Iraqi officials, including Prime Minister Nuri al-Maliki, moved closer to Mr. Obama’s position.

If the conflict in Vietnam was notable for open access given to journalists — too much, many critics said, as the war played out nightly in bloody newscasts — the Iraq war may mark an opposite extreme: after five years and more than 4,000 American combat deaths, searches and interviews turned up fewer than a half-dozen graphic photographs of dead American soldiers.