Republican John McCain has portrayed Barack Obama as focused on his own ambition over military success in Iraq, as the Democrat argued that McCain favours extending a war that is hurting Americans at home.
McCain mocked what he called Obama's varying positions on the so-called "surge" that sent an additional 30,000 troops to Iraq last year but that was unpopular with the American public. Obama opposed the strategy at the time and has suggested that he would pull US combat troops out of Iraq within 16 months of taking office.
McCain has increasingly tried to portray the Illinois senator as an ambitious but empty celebrity, a man with a way with words but not the expertise or experience to back his rhetoric. The 71-year-old military veteran's comments echoed an earlier statement that raised eyebrows when he appeared to question Obama's patriotism, charging that he "would rather lose a war in order to win a political campaign".
In his speech to the Disabled American Veterans convention on Saturday, McCain said Obama had not only predicted the troop increase would not succeed but had taken steps to ensure its failure, saying Obama had tried to prevent needed funding for it.
"Not content to merely predict failure in Iraq, my opponent tried to legislate failure," McCain said.
Obama voted against one major military appropriations bill in May 2007, but otherwise has voted consistently for funding to support the war, even though he opposed the initial invasion.
The surge has been credited with helping stabilise Iraq and reduce violence there. Obama has argued that it has not brought about the political reconciliation between rival Sunni and Shia factions needed to create lasting peace in the country.
Obama has consistently criticised McCain for supporting the original Iraq invasion, which polls show many voters now consider a mistake. Obama, who has made Afghanistan a centrepiece of his anti-terrorism strategy, has said the protracted Iraq conflict has drawn needed resources away from Afghanistan where al-Qaeda and Taliban forces have shown a resurgence.
He also said while beginning a week-long vacation in Hawaii that McCain's embrace of President George W Bush's policies short changed Americans by favouring an extended war in Iraq at the expense of fixing underfunded schools and crumbling roads and bridges.
Obama used a national radio address to trumpet his campaign proposals to end US dependence on foreign oil by investing in alternative energy and to conclude the war in Iraq responsibly "by asking the Iraqis to take responsibility for their future and to invest in their own country".
He pointed to a recent Government Accountability Office report that found the Iraqi government could end the year with a $US79 billion ($A87.28 billion) budget surplus while spending only a fraction on reconstruction costs that are largely borne by the US.
"Senator McCain talks about putting our country first, but he is running for a third term of the very same policies that have set our country back," he said.
Money spent in Iraq could have been used to help develop alternative energy and create jobs, he argued, "and begun to end the tyranny of oil in our time."
Also on Saturday, Democrats met in Pittsburgh to debate the party's platform. On Iraq, the draft states that Democrats "expect to complete redeployment within 16 months". That reflects Obama's time frame, but with less certainty than he has expressed.
Party platforms are a statement of principles that are not binding on the candidates or the next president and they are typically given little attention after they are adopted.
The Democrats' platform also includes a guarantee to health care for all Americans, support of women's rights, energy rebates to struggling families, a crackdown on predatory lenders, higher taxes for families earning over $250,000, tax breaks for others, billions for economic stimulus and "direct high-level diplomacy, without preconditions", in the case of Iran.
Earlier on Saturday, McCain jabbed at Obama in his weekly radio address, saying he anticipated an impressive speech at the Democratic convention later this month.
"Even the most stirring speeches are easily forgotten when they're short on content. Taking in my opponent's performances is a little like watching a big summer blockbuster, and an hour in realising that all the best scenes were in the trailer you saw last fall," McCain said.
Obama's campaign plane arrived Friday in Hawaii, with 17 of his friends and family members filling the seats normally occupied by his travelling advisers. The band included his wife, Michelle, 10-year-old daughter Malia and seven-year-old daughter Sasha.
They were staying with friends and family on Oahu, where his sister, Maya Soetoro-Ng, and 85-year-old grandmother, Madelyn Dunham, live. Obama's grandmother helped raise him, but Obama has said osteoporosis keeps her from travelling and instead she follows campaign coverage closely on CNN.
