WASHINGTON (JTA) -- In one corner was the Center for American Progress, or CAP, arguably Washington’s leading liberal think tank. In the other was Josh Block, a pugnacious former spokesman for the American Israel Public Affairs Committee, who aggressively pushed the notion to reporters that CAP has an Israel problem.

Nearly two months after their dispute made headlines, both parties have been left bloodied -- and some in the pro-Israel community say they wish the issue had never played out in such a public way.

“We have been contacted by a couple of people" at CAP "who want to see some peace,” said Jason Isaacson, director of government and international affairs at the American Jewish Committee. “We don't want a war with CAP, although that probably is the intention of some people.”

Today, CAP is noticeably more careful about how its affiliated Think Progress and Middle East Progress blogs treat the issue of Israel. Block, meanwhile, was ousted from the Truman National Security Project, a network of young Democrats with an interest in foreign policy, for what it described as "uncivil discourse."

At issue in the controversy were posts on the Think Progress and Middle East Progress blogs that either criticized Israel and its American allies -- sometimes in harsh terms -- or questioned calls for a tougher line on Iran. In addition, there were personal tweets by a Think Progress blogger that used the words “Israel Firster” -- a phrase that many in the Jewish community feel is anti-Semitic -- to disparage some supporters of Israel.

Late last year, Block shopped to reporters with whom he had longstanding ties a file of what he portrayed as statements that he said showed CAP, as well as the liberal group Media Matters, using the “words of anti-Semites.” Politico was the first to bite, running a story Dec. 7 that said CAP and Media Matters were “challenging a bipartisan consensus on Israel and Palestine that has dominated American foreign policy for more than a decade.”

The story quickly garnered attention, and it proved to have legs. On Jan. 19, the Washington Post reported on the anger of Jewish groups over some of the Israel rhetoric employed by CAP bloggers.

CAP has responded throughout by emphatically denying charges that it is hostile to Israel and insisting that its bloggers’ writings do not necessarily reflect the organization’s position.

CAP emailed a statement to JTA noting the group's "zero tolerance" for anti-Semitism and other forms of bias.

"The Center for American Progress is and always has been pro-Israel, committed to a peace process that produces a durable two-state solution negotiated by the parties, and it takes seriously the threat posed by Iran and its nuclear activities,” CAP said in its statement. “The overwhelming record from hundreds of our articles, posts, and policy papers demonstrates our support for the longstanding bipartisan consensus that the two-state solution is in the moral and national security interests of the United States."

CAP officials, seeking to contain the controversy's fallout, have instructed staffers and others close to the organization not to speak to the media.

But figures close to the think tank, speaking on condition of anonymity, said they perceive Block’s efforts as an attempt to keep views critical of Israel out of the discourse or challenge what they see as pieties about the dangers posed by Iran. They also acknowledged, however, that since the controversy broke, CAP has become more careful about moderating its writers’ language on the topic.

Officials at some pro-Israel groups expressed frustration with the public attack on CAP at a time that they were trying to address their differences with the group through quiet diplomacy. A number of Jewish organizations had been making representations to CAP before the Politico story was published.

“At the highest levels of AIPAC, there is a philosophy of never going to the media with policy disputes,” an AIPAC official said on condition of anonymity.

“We’re not happy this has taken the course it has,” the official added. “We would have preferred it was dealt with quietly.”

Block declined to respond to suggestions by some Jewish communal officials that the issue should have been handled more discreetly. But within minutes of Block being approached for comment, the same AIPAC official, spurred by Block, called JTA and said that he would prefer not having his quote used. But he agreed that since he had said it for the record, it was fair to publish.

The AIPAC official made clear that his organization remained frustrated with CAP. Top AIPAC officials would meet with top CAP officials, the official said, and these meetings would conclude with an agreement by CAP to monitor blog posts more closely. AIPAC recently took CAP officials on an Israel tour, the official noted.

Yet CAP and its Middle East shop in particular would consistently return to what AIPAC perceived as unfair depictions of the policies of Israel and its supporters.

The stakes are high because of CAP’s perceived closeness to the White House and its centrality in Washington’s Democratic policy community. In 2008, Time Magazine called it “the most influential independent organization in Obama’s nascent Washington.”

Block says that CAP has allowed its bloggers to peddle distortions and falsehoods that demonize the pro-Israel community.

"As long as CAP chooses to have people writing the organization's day-to-day views on national security and Middle East issues who truck in language and theories more at home on White Power and anti-Jewish conspiracy websites than in the mainstream of the Democratic Party, CAP's work will be judged accordingly and the organization will continue to see its credibility erode,” Block told JTA.

Block is not alone in his distaste for some of CAP’s rhetoric.

“There were certain things that CAP was responsible for putting in the public arena that were not fair to Israel's strategic situation and people who are sympathetic to Israel's situation,” the AJC's Isaacson said.

Perhaps the most incendiary items were tweets by Think Progress staffer Zaid Jilani, who several times used the term “Israel Firster” on his private Twitter feed.

In the wake of the Politico article, three Jewish groups -- the Anti-Defamation League, the American Jewish Committee and the Simon Wiesenthal Center -- expressed alarm. The term, the ADL says, plays “into the old anti-Semitic notion that Jews are more loyal to some foreign entity than to their own country.”

CAP repudiated the term “Israel Firster,” and Jilani expunged from his Twitter feed the posts that used the term.

Sources close to CAP said Jilani, who is 23 and has since left CAP, used the term because it had the imprimatur of repeated use by M.J. Rosenberg, a one-time AIPAC staffer who long ago turned against the organization and now blogs for Media Matters, another target of Block’s ire. Rosenberg is a figure known in the left-leaning Middle East policy community as an analyst who can be incisive but who frequently veers into provocative rhetoric and name calling.

Rosenberg deferred comment on this matter, directing queries to Ari Rabin-Havt, Media Matters’ executive vice president. In an interview, Rabin-Havt said the terminology was beside the point.

“When we're talking war and peace, the facts that tweets come up is symbolic of how the conversation has gone awry,” said Rabin-Havt, who said the survival of Israel was critical to him personally. “We should debate this. As Israel is one of our largest recipients of foreign aid, this is an American and Israeli issue.”

Yet it is the contours of that very debate that trouble pro-Israel groups. Abraham Foxman, the ADL’s national director, singled out an article by Eli Clifton, a Think Progress staffer, that seemed to suggest that AIPAC was driving the country toward war with Iran.

In an Aug. 10 post, Clifton described an AIPAC statement applauding a bipartisan Senate letter urging sanctions on Iran’s central bank as drawing “eerie parallels between the escalation of sanctions against Iran and the slow lead-up to the invasion of Iraq in 2003."

Foxman said it was legitimate "to say that there are those in the Jewish community who feel very strongly about confronting Iran. But when it’s linked to a conspiratorial view of the Iraq war, ‘It's the Israel lobby, it's the Jewish community,’ that parrots a line.”

Sources close to CAP say the organization recognizes how Clifton’s language may have been problematic, and that it would be more useful to describe groups like AIPAC as backing measures that could escalate into military conflict, as opposed to accusing AIPAC of seeking war.

AIPAC does not advocate war with Iran. In public and private forums, top AIPAC officials have made clear their fears of the consequences of military conflict.

In a later clarification appended to Clifton's post, Think Progress said that "Given Iran’s horrible record on human rights abuses and outright hostile and anti-Semitic rhetoric towards Israel, an Iran with nuclear weapons is very concerning and we support responsible measures to reduce that threat."

In a Dec. 7 email forwarding the Politico story about the controversy to reporters, Block pointed to examples of what he said were provocative writings from CAP. But he included blog posts suggesting that Iran might be further away from a nuclear weapon than is commonly believed and advocating deterrence as opposed to an escalating confrontation.

"CAP authors have long sought to both debunk and sneer at suggestions of Iranian nuclearization, right through this morning," he said. "This flies in the face of overwhelming congressional and center-left conviction that Iran is nuclearizing and that a robust sanctions regime is necessary to counter their efforts."

CAP's position on Iran is that it backs multilateral sanctions but opposes attempts in Congress -- and backed by some pro-Israel groups -- to impose sanctions unilaterally. It is the lumping together of criticisms of policy positions with accusations of anti-Semitism that infuriates CAP supporters.

"It was clearly a smear campaign against people, not because they are anti-Semitic, but because he disagreed with them on policy,” said Dave Solimini, the Truman National Security Project’s spokesman.

Block, who is a partner in a Washington consulting firm and a senior fellow at the centrist Progressive Policy Institute, has said that he is not bothered by being ousted from the Truman Project.

He expresses pride in what he sees as his role in spurring CAP to change.

“I don’t think this is who CAP, its new leadership or its allies want the organization to be,” Block said. “I hope we will see more meaningful corrective measures in the future.”