PHILADELPHIA - Both Democratic presidential candidates threatened a tough response to Iran should it attack Israel, while sparring over the role of faith in American life and the validity of judging their candidacies by those with whom they associate during a debate Wednesday night. "An attack on Israel would trigger massive retaliation from the United States," said New York Sen. Hillary Clinton, who proposed that the US create a security umbrella for Israel and other allies in the region to protect them from a nuclear Iran. "So would an attack on those countries that are willing to go under the security umbrella and forswear their own nuclear ambitions." Clinton pointed to Saudi Arabia and the UAE as states that had concerns about Iran's nuclear ambition. "We've got to deter other countries from feeling they have to acquire nuclear weapons," she said. Both she and her rival for the Democratic nomination, Illinois Sen. Barack Obama, had been asked whether it should be US policy to treat an Iranian attack on Israel as an attack on the US. "The United States would take appropriate action," Obama said in response to the question, terming such an attack an "unacceptable" act of aggression. "It is very important that Iran understands that an attack on Israel is an attack on our strongest ally in the region, one whose security we consider paramount." The Illinois senator stressed that he would "take no option off the table" when it comes to preventing Iran from attaining a nuclear weapons program. Both presidential candidates, though, emphasized the role of diplomacy in dealing with Iran. Apart from questions on Iran and Iraq, foreign policy took a back seat at the ABC/WPVI-TV debate, which took place in National Constitutional Center here just six days ahead of the crucial Pennsylvania primary on Tuesday. Clinton is desperate for a victory to keep her presidential hopes alive, while Obama would like to nullify her argument that she's more electable among the white working class voters here and elsewhere, a key demographic in the national race. So far Clinton is leading in the polls. With the battle between the two personalities intensifying, the debate focused on recent missteps and controversies that have dominated campaign coverage in recent days, as well as questions about whether they felt their competitor could beat McCain (two yeses) and whether they would run on a joint ticket (two dodges). Obama has been heavily criticized for comments he made last week that voters facing economic hardship "get bitter, they cling to guns or religion or antipathy to people who aren't like them or anti-immigrant sentiment or anti-trade sentiment." Obama clarified his words during the debate, saying they had been "mangled up," "The point I was making was that when people feel like Washington's not listening to them, when they're promised year after year, decade after decade, that their economic situation is going to change, and it doesn't, then politically they end up focusing on those things that are constant, like religion." But Clinton attacked his clarification, saying that she didn't think that people cling to religion when Washington is not listening to them. "I think that is a fundamental, sort of, misunderstanding of the role of religion and faith in times that are good and times that are bad," she said. Clinton herself had to address her misstatements that she came under sniper fire when arriving in Bosnia as first lady when she hadn't, something she called a "mistake" that she was "embarrassed" about Wednesday night. Obama said that both candidates had said things they regretted. "Sometimes that message is going to be imperfectly delivered, because we are recorded every minute of every day. And I think Sen. Clinton deserves, you know, the right to make some errors once in a while. Obviously, I make some as well." The hubbub over Obama's ties to Jeremiah Wright also continued, despite his campaign's efforts to move past the revelations of his former pastor's incendiary comments about white America and statements highly critical of Israel. "It is clear that, as leaders, we have a choice who we associate with and who we apparently give some kind of seal of approval to," Clinton said, after the debate moderations raised the issue of Wright. "And I think that it wasn't only the specific remarks, but some of the relationships with Reverend Farrakhan, with giving the church bulletin over to the leader of Hamas to put a message in. You know, these are problems, and they raise questions in people's minds."