US President Barack Obama castigated Republican rival Mitt Romney for insulting top ally Britain today and said he was not ready for international diplomacy.
"You might not be ready for diplomacy with Beijing if you can't visit the Olympics without insulting our closest ally," Obama said in a pitch to American voters as he accepted the Democratic Party's presidential nomination.
Obama trumpeted his own foreign policy and national security successes as he launched a blistering attack on his opponent in November, trying to persuade American voters he was the only candidate suitable of being commander-in-chief.
"In a world of new threats and new challenges, you can choose leadership that has been tested and proven," he said.
"Four years ago, I promised to end the war in Iraq. We did. I promised to refocus on the terrorists who actually attacked us on 9/11. We have," he said.
"I promised to refocus on the terrorists who actually attacked us on 9/11. We have. We've blunted the Taliban's momentum in Afghanistan, and in 2014, our longest war will be over.
"A new tower rises above the New York skyline, al Qaeda is on the path to defeat, and Osama bin Laden is dead."
Obama contrasted his sterling record with that of an opponent he portrayed as clearly not ready for the Oval Office.
"My opponent and his running mate are new to foreign policy, but from all that we've seen and heard, they want to take us back to an era of blustering and blundering that cost America so dearly," he said.
"After all, you don't call Russia our number one enemy - and not al Qaeda - unless you're still stuck in a Cold War time warp," he said to raucous cheering from a convention hall in North Carolina packed with party faithful.
"My opponent said it was 'tragic' to end the war in Iraq, and he won't tell us how he'll end the war in Afghanistan," he said. "I have, and I will."
The Olympics barb was particularly scathing, coming after Romney arrived in London for the Olympics in July and promptly questioned the preparations, suggesting that the host nation might not be fully behind the Games.