WATERTOWN, S.D. - Sen. Barack Obama responded sharply on Friday to attacks on his foreign policy, linking President Bush and Sen. John McCain as partners in "failed policies" and criticizing them for "hypocrisy, fear-peddling, fear-mongering."

"If they want a debate about protecting the United States of America, that's a debate I'm ready to win because George Bush and John McCain have a lot to answer for," Obama said, citing a litany of what he called blunders by the Bush administration and accused McCain, the presumed Republican nominee, of "doubling down" on them.

Among their failings, Obama listed the Iraq war, the strengthening of Iran and groups such as Hamas and Hezbollah, Osama bin Laden's being still at large and stalled diplomacy in other parts of the Middle East.

His defiance and disdain for Bush's record appeared to be a signal that he will push back against efforts to define him or his record as weak on terror or accommodating to foreign foes, a strategy Republicans used successfully against Sen. John Kerry in 2004.

The appearance also signaled that the campaigns are pivoting swiftly toward the general election, with the two sides already in full attack mode.

Throughout his comments, Obama yoked Bush and McCain as an entity, mentioning their names in the same sentence 10 times in barely 10 minutes. He portrayed them as being not only inflexible, but also "naive and irresponsible" -- characteristics they ascribe to him.

"In the Bush-McCain world view, everyone who disagrees with their failed Iran policy is an appeaser," Obama said.

McCain's campaign answered quickly and sharply on Friday. A spokesman, Tucker Bounds, called the remarks a "hysterical diatribe in response to a speech in which his name wasn't even mentioned."

Said McCain: "It would be a wonderful thing if we lived in a world where we don't have enemies. But that is not the world we live in, and until Senator Obama understands that reality, the American people have every reason to doubt whether he has the strength, judgment and determination to keep us safe."

The dustup began a day earlier, when Bush gave a speech to the Israeli Knesset in which he criticized those who believe the United States should negotiate with terrorists and radicals. Obama said Bush's criticism was directed at him, and took umbrage; the White House denied any such intention.