WATERTOWN, South Dakota (Reuters) - Democratic presidential front-runner Barack Obama said on Friday President George W. Bush’s “failed policies” had strengthened U.S. enemies like Iran and Hamas.

Responding to Bush’s comment on Thursday that those who want to talk to Iran were like Nazi appeasers before the Second World War, Obama accused Bush of “exactly the kind of appalling attack that’s divided the country and that alienates us from the world.”

Obama also challenged Bush and Republican presidential rival John McCain to a debate on foreign policy issues, a day after Bush caused outrage among Democrats with his remarks on appeasement before the Israeli parliament.

McCain, who has clinched his party’s presidential nomination, did not repeat the word “appeasement” on Thursday. But he did criticize Obama’s pledge to speak directly to U.S. foes, particularly Iranian President Mahmoud Ahmadinejad. He said Obama needs to explain why he would talk to him.

“If George Bush and John McCain want to have a debate about protecting the United States of America, that is a debate that I’m happy to have any time, any place, and that is a debate that I will win because George Bush and John McCain have a lot to answer for,” Obama said in a campaign speech in South Dakota.

“They’ve got to answer for the fact that Iran is the greatest strategic beneficiary of our invasion of Iraq. It made Iran stronger, George Bush’s policies,” he said.

“They’re going to have to explain why Hamas now controls Gaza, Hamas that was strengthened because the United States insisted that we should have democratic elections in the Palestinian Authority.”

“That’s the Bush-McCain record on protecting this country,” he added. “Those are the failed policies that John McCain wants to double down on.”