WASHINGTON (JTA) - For years the pro-Israel lobby has been pushing more punitive steps to deter Iran's nuclear ambitions. But with enhanced US sanctions increasingly likely by early next year, opponents and supporters agree that the case was finally made - by Iran itself. The key to an accelerated path to a sanctions bill that insiders now believe will land on President Barack Obama's desk within a month was Iran's belligerent rejection of a Western offer to substantively enhance its peaceful nuclear program in exchange for greater transparency. "There's no lack of appetite for passing the sanctions," said an official of one of the pro-Israel groups that has pushed for legislation targeting third parties, including countries that deal with Iran's energy sector. "It's evident," the official said, that the Iranians "do not want talks. They're not going full speed ahead, they're going full nuclear ahead." Even a leading opponent of sanctions, such as Trita Parsi, who heads the National Iranian American Council, conceded that such a measure now seems inevitable - and that the Iranian government's behavior in recent weeks was behind the accelerated pace. "There's a very justified disappointment with how the negotiations have gone and with how the Iranians have conducted the negotiations," he said. In October, Iran initially accepted the offer to hand over much of its low-enriched uranium to Russia and France for further enrichment to medical research levels. It also agreed to allow inspectors to examine a second, secret nuclear enrichment plant at Qom, just days after Obama revealed its existence based on Western intelligence reports. Within weeks, however, Iran reneged on the deal - despite claiming that it had suggested the deal in the first place - and obstructed inspectors from the International Atomic Energy Agency, the UN nuclear watchdog, from thoroughly investigating the second enrichment site. Parsi asserted that the resistance arose not from a regime implacably opposed to engagement with the West, but instead from elements that oppose Mahmoud Ahmadinejad's government and seek to undermine it by painting the government as undermining Iran's national interests. The paradox, Parsi said, is that these elements are otherwise perceived in the West as friendlier to rapprochement. Nonetheless, Iran's recidivism led two of the most critical opponents of enhanced sanctions - China and Russia - to join in an IAEA resolution blasting Iran for not cooperating. Iran countered that it would build an additional 10 enrichment sites. Iran's actions whittled away the reluctance of a number of key players who had worried that new sanctions would preempt Obama's efforts to resolve the crisis through direct talks with Teheran - chief among them the president himself, who is now considered likely to sign a sanctions bill. It was Obama who dispatched his most prominent Iran hawk, Dennis Ross, and Jeffrey Bader, both senior staffers on the National Security Council, to China in late October to make the case for signing on to the IAEA resolution. Ross' argument reportedly was simple but effective: Help contain Iran, or we won't be able to contain Israel. Another domino to drop was US Rep. Howard Berman (D-Calif.), the chairman of the House of Representatives Foreign Affairs Committee. He not only lifted his hold on the proposed House legislation, but now is fast tracking it for a vote by next week. There are similar plans in the Senate, although they may be delayed past the Christmas break because of the vexed health care debate. In the American Jewish community, tougher sanctions have been pushed for at least a decade by the American Israel Public Affairs Committee and, more recently, by other established pro-Israel organizations. The Conference of Presidents of Major American Jewish Organizations, a politically and denominationally diverse umbrella organization consisting of more than 50 groups, issued a statement over the weekend urging both chambers of Congress to pass sanctions legislation by the end of the year if possible. "The timing for this vote is especially significant," said Presidents Conference chairman Alan Solow and executive vice chairman Malcolm Hoenlein in the statement. "Should the IRPSA legislation pass the House, it has the potential to seriously impact the Iranian economy. The prospect of the sanctions in this bill and the Iran Sanctions Enabling Act, which overwhelmingly passed the House in October, are essential to pressing Iran, the leading violator of human rights and state sponsor of terrorism globally, against pursuing a nuclear weapons capacity." Signaling just how widespread Jewish organizational support is for the sanctions, they now have the support of J Street, which had advocated stepped-up US diplomacy rather than confrontation. For months, J Street has said it backed the sanctions in principle but opposed pushing them forward while engagement was under way. But on Monday the group issued a statement expressing support for the congressional measures, citing "Iran's continued defiance of the international community and its rejection of the most recent diplomatic offer on nuclear enrichment." "We're not jumping for joy for supporting this legislation," said Hadar Susskind, J Street's political director. "Iran has showed itself to be bad actor." Only Americans For Peace Now continues to oppose sanctions, saying they would backfire by turning Iranians toward a regime now fending off accusations of illegitimacy. The group is lobbying Congress to loosen the legislation's restrictions on the president's ability to waive the sanctions - saying that tying his hands undermines their usefulness as a diplomatic stick. "Rather than 'empowering' the President with additional authority," as the bill promises, Americans for Peace Now said in a letter to House members, "HR 2194 would sharply limit his authority regarding both existing sanctions and potential new ones." Parsi, of the Iranian Council, said rushing forward the unilateral US sanctions would undercut efforts by Obama to sign on the international community to multilateral sanctions by early next year, adding that unilateral sanctions might have the effect of alienating Russia, China and key European nations by targeting major companies in those nations. "Are you going to have a bomb by Christmas Eve?" Parsi asked, referring to the accelerated congressional schedule. "You don't want to give the impression that people are dying to go for sanctions because that casts the diplomacy in doubt." Underscoring the sinking standing of the Iranian regime, Parsi's organization blasted the Obama administration this week for not making human rights as much a priority as nuclear weapons. "Iran's human rights abuses must be addressed now and not just when our focus turns to punitive measures," he wrote in a column on the Huffington Post blog. "Otherwise, the administration will unintentionally signal that the rights of the Iranian people are used solely as a pressure tactic against Iran when it fails to compromise on other issues."