Some 6,500 American Israel Public Affairs Committee activists attending the organization's annual conference will be hitting Capitol Hill next week to stress the importance of the US-Israel relationship and push legislation imposing sanctions on Iran. But the conference, which begins on Sunday, comes as the Obama administration is staking out different ground from Israel on Iran and the peace process - a divergence some Jewish activists critical of AIPAC have seized on. The climate poses challenges as AIPAC tries to push its lobbying agenda. The White House on Wednesday rebuffed Israeli calls for the US to put a time limit on its engagement with Iran and to act speedily as Teheran makes progress mastering nuclear capabilities. National Security Council spokesman Mike Hammer said "it's not appropriate at this time to be trying to establish timetables but rather seeing how the engagement can move forward" and that "we are in a process that we expect will take some time." And when it comes to the Israeli-Palestinian peace process, according to an interview published in The Washington Post Thursday, National Security Advisor Gen. James Jones thinks the US should propose its own ideas - a proposition many Israelis are uncomfortable with. Jones is quoted as saying, "If we want to get momentum, we have to be involved directly." At the same time, the progressive J Street lobby is opposing the Iran legislation AIPAC is championing, coming out strongly in favor of the Obama administration's approach of engagement on Israel and Iran and calling on its supporters to contact members of Congress to make that point. The new Iran sanctions bills would increase the president's ability to punish international companies that help Iran obtain refined petroleum. It was introduced Tuesday in the Senate by sponsors Evan Bayh (D-Indiana), John Kyl (R-Arizona) and Joe Lieberman (I-Connecticut), with similar companion legislation submitted by the chairman and ranking member of the House Foreign Affairs Committee, Howard Berman (D-California) and Ileana Ros-Lehtinen (R-Florida), late Thursday. "AIPAC strongly supports congressional measures to create the leverage we need for constructive diplomatic engagement to have a chance to work. If Iran doesn't act rapidly to suspend its enrichment and other illicit nuclear work, the US and our allies must be prepared to induce Iranian compliance by targeting Iran's economic and structural vulnerabilities," said AIPAC spokesman Josh Block. "This bill gives President Obama the tools to do just that." But the legislation, while having significant bipartisan support that bodes well for its eventual passage, is being held up from the get-go by Berman himself, who noted in a press release that "I have no intention of moving this bill though the legislative process in the near future." "I share President Obama's conviction that it is unacceptable for Iran to possess nuclear weapons and his determination to seek a diplomatic solution to this issue," he explained. "However, should engagement with Iran not yield the desired results in a reasonable period of time, we will have no choice but to press forward with additional sanctions - such as those contained in this bill - that could truly cripple the Iranian economy." A congressional aide described it as a "sword of Damocles" to show Iran what awaits it if the negotiations don't work out. The legislation also sends a signal to the administration about what's in store for it if engagement falters - both in terms of enhancing the range of options at its disposal and in terms of the congressional pressure it might face to take stronger action. "It keeps the discussion going in the body politic about sanctions and corporate divestment as being something that's important on an advocacy level," said one Washington pro-Israel activist, describing the legislation as a reminder that "while the president's playing with his carrots there are a lot of people who think the sticks are important too." The activist added that it was important that the legislation be introduced this week even if it isn't acted on soon because "6,000-plus people are going to come to Washington next week and they need something to talk about that's Iran-related." The White House did not respond to questions from The Jerusalem Post on whether it would support the legislation, but a State Department official said the administration was aware of the proposals. "We have been reviewing the draft legislation and its implications. It's important that any legislation not interfere with the administration's ability to conduct its diplomacy," he said. "We intend to pursue direct and honest diplomacy with Iran on all issues to overcome our real differences and explore areas of shared interest. We urge Iran to take advantage of this opportunity for engagement." Speaking about the US posture toward Iran generally, Hammer said Wednesday that the administration was focused on moving engagement forward while US Secretary of State Hillary Clinton spoke of "crippling" sanctions against Iran "should we need it" in testimony before Congress last week. The impression on Capitol Hill, though, is that the administration is less than pleased at the prospect of additional sanctions being slapped on Iran in the near term. Holding off on pushing the legislation forward could avoid a tussle with the White House on how to proceed on the sensitive issue. Having the legislation in the wings, on the other hand, could be helpful if the administration does want to move in the future to increase pressure on Iran and the European companies that do business with it by pointing to what Teheran might face from Congress. J Street, for its part, argues that imposing further sanctions on Iran is "directly undercutting the president's diplomatic message" and is urging those on its email list - which it counts as more than 100,000 strong - to contact members of Congress to make that case. J Street is also calling on its supporters to tell their members of Congress "to support President Obama's vision for US policy in the Middle East" to the tune of $900 million in funding for the Palestinians. AIPAC, which supports the Palestinian funding, is also preparing a letter that appears to bridge some of the gaps between Israeli and American thinking on the Israeli-Palestinian peace process, as it emphasizes establishing the institutions for a Palestinian state - a position somewhere between Prime Minister Binyamin Netanyahu's preference for Palestinian economic improvement leading toward autonomy, and the urgency the US has put on working toward a two-state solution - and urges direct negotiations between the parties, rather than solutions imposed from other players. J Street is officially making no connection between its action alert and AIPAC's own lobbying day next Tuesday, and J Street officials have pointed to the introduction of the legislation this week to explain the timing. Jewish community officials in Washington, though, see the effort as a direct challenge to AIPAC. Either way, one progressive Jewish Washington insider contended that the new lobbying outfit is going to complicate AIPAC's case. "It definitely makes it harder for AIPAC. If there's overwhelming support or opposition for something in the Congress, then it's very hard for lobby groups smaller than AIPAC to make a difference," he said. "But when there are widespread differences, then the J Streets of the world can have much more effect." But long-time Israel advocate Morrie Amitay disagreed. "You've had these on-their-knees types coming out of the woodwork all the time," asserted the former executive director of AIPAC. "AIPAC's going to have 6,000-7,000 people [present]. They have over 100,000 members. They've been around since 1957," he continued. "You're comparing an ant to an elephant." One Washington Jewish organizational leader not affiliated with either camp agreed with Amitay that J Street was no match for AIPAC. "AIPAC, in terms of money and influence, clearly overwhelms J Street," he said, "but it's pretty interesting to see them [decide] to directly take on AIPAC on a legislative issue." He predicted that "there's no question the majority of members of Congress are going to vote the way AIPAC wants them to," if for no other reason than that sanctioning Iran is a popular cause among Americans generally. "They [J Street] are not going to win, but they're building their voice and building their credibility," he said. "Next time, there'll be more people listening to them."