Senate Majority Leader Harry Reid (D-Nev.) is in quite a pickle. In refusing to bring the House’s Iran sanctions bill (passed in December) to the Senate floor for an up-or-down vote, it becomes almost certain that there will be no bill or it will be sent into deep freeze in a conference committee.

Republicans in the Senate would like to get something, even a “Sense of the Senate” measure that the credible threat of the use of force is an essential U.S. policy toward Iran. But if Reid agrees to include that, Sen. Rand Paul (R-Ky.) would, in all likelihood, refuse to a unanimous-consent procedure, forcing a vote and a flood of amendments (all of which could have been done in the last five months). With or without the Sense of the Senate language, it is hard to see how anything meaningful is accomplished by the time the P5+1 resumes talks with Iran on Wednesday.

Now it might be wise, since there will be a conference committee anyway, for Republicans to vote on whatever is there, just to get the sanctions bill into conference. According to sources on the Hill, moderate Democrats have privately said they would side with Senate Republicans and the House Foreign Affairs Committee chairwoman in conference in pushing for robust sanctions.

It is noteworthy that the White House is doing nothing significant to hasten passage of the crippling sanctions they keep talking about. That has fueled suspicion that Obama views sanctions as unimportant or even counterproductive in his effort to get a deal with Iran.

A senior GOP adviser authorized only to speak on background picked up on the Romney campaign’s Neville Chamberlain reference, “As President Obama gets his umbrella ready, members of Congress on both sides of the aisle know that the only potential winner in Baghdad may be the Islamic Republic of Iran. The American people will not allow Baghdad 2012 to replace Munich 1938 in tomorrow’s history textbooks. If the President celebrates any Iranian commitment short of full compliance with multiple UN Security Council Resolutions, ‘peace in our time’ will quickly be replaced by ‘F-16s in their airspace.’ ”

But let’s play that out in terms of U.S. politics. If Obama comes back next week with a phony deal on Iran’s nuclear weapons program, one designed just to buy him more time to try to stave off Israeli action, Republicans, especially his election opponent, certainly will call him out. But things really get dicey for pro-Israel Democrats.

If such a deal (e.g. less than full, verifiable cessation of weapons-grade uranium enrichment) comes about next week, stalwart pro-Israel lawmakers, especially those on the ballot in tricky races — such as Rep. Howard Berman (D-Calif.) and Sens. Robert Casey, Jr. (D-Pa.), Bill Nelson (D-Fla.), Robert Menendez (D-N.J.), and Kirsten Gillibrand (D-N.Y.), as well as Nevada Senate candidate Rep. Shelley Berkley — will be between a rock and a hard place. If they cross the president and criticize an Iran deal as a farce, they split the Democratic Party on a major national security issue. If they say, “Well, sanctions are working and this buys us more time, so we have to give the president some room here . . . blah, blah, blah,” then they risk their own credibility and hand a club to their opponents with which to beat them over the head in the election.

Obama’s Iran policy has been resting on a convenient fiction — namely, that sanctions would get the Iranians to give up their nuclear weapons program. Republicans who never believed sanctions would work can say, when sanctions failed, that they had tried everything. Democrats who never wanted to take more robust action could kick the can down the road. But now we’re at the end of the road and everyone must decide what to do.

And if there is no deal, just an agreement once again to have a meeting, does the president acknowledge his Iran policy has failed and move to make good on his vow that the U.S. would use all means needed to prevent a nuclear-armed Iran? The stakes could not be higher, in large part because we know Israeli Prime Minister Bibi Netanyahu has prepared in every way possible to take military action if needed.