In the video, bin Laden attacked capitalism, multinational corporations and globalization.
"This is why I tell you: as you liberated yourselves before from the slavery of monks, kings and feudalism, you should liberate yourselves from the deception, shackles and attrition of the capitalist system," he said.
Several current and former government officials said they believed an American - 28-year-old Adam Gadahn - may have written at least part of the speech.
Gadahn, who has been charged with treason and supporting terrorism for serving as an al-Qaida propagandist, has appeared in several past al-Qaida-produced videos, lecturing against capitalism and globalization and making insider references to American culture.
"It has Adam Gadahn written all over it," one former senior intelligence official said of bin Laden's tape, speaking on condition of anonymity because of the sensitivity of the issue.
In the new video, bin Laden derided President Bush, saying events in Iraq have gotten "out of control" and the American leader "is like the one who plows and sows the sea: He harvests nothing but failure."
Bush made the rare move of speaking about an al-Qaida video. The tape is "a reminder about the dangerous world in which we live," he told reporters on the sidelines of a summit of Pacific Rim nations in Sydney, Australia.
"It's important that we show resolve and determination to protect ourselves, deny al-Qaida safe haven and support young democracies," Bush said.
Bin Laden said there were two solutions to stopping the Iraq war. "One is from our side, and it is to escalate the fighting and killing against you. This is our duty, and our brothers are carrying it out," bin Laden said.
"The second solution is from your side. ... I invite you to embrace Islam," he said.
One result of that, bin Laden said, would be an end to the Iraq war. He said "warmongering owners of the major corporations" would rush to appease voters who showed they are looking for an alternative, "and this alternative is Islam."
