In a show of defiance to President Obama, 13 Democratic Senators joined 13 Republicans in introducing a new Iranian sanctions bill that includes language forcing the US to support Israel in the event they attack Iran's nuclear facilities.

The president has threatened to veto the bill, and it is uncertain if Majority Leader Harry Reid will even allow the bill to come to the floor for a vote.

Republican Mark Kirk is leading the charge.

Associated Press:

"Current sanctions brought Iran to the negotiating table and a credible threat of future sanctions will require Iran to cooperate and act in good faith at the negotiating table," said Sen. Bob Menendez, D-N.J., who spearheaded the effort with Sen. Mark Kirk, R-Ill.

Kirk called the draft law "an insurance policy to defend against Iranian deception."

The Obama administration has furiously lobbied Congress not to impose new sanctions, even on a conditional basis, saying the increased economic pressure could force Iran to withdraw from the negotiating process and strain ties between the United States and its key negotiating partners -- Britain, China, France, Germany and Russia. Washington is banking on these countries to persuade Tehran into accepting a final package that would ease trade, financial and oil restrictions if the Iranian government severely rolls back its uranium enrichment activity and other elements of its nuclear program.

Iran's foreign minister also has said new sanctions could scuttle hopes of a diplomatic resolution. Iran maintains its program is solely for peaceful energy production and medical research purposes, but the United States and many other countries harbor severe doubts. Israel is perhaps most adamant in insisting Iran's true intentions are to develop an atomic weapons arsenal.

The White House said it didn't think the Senate bill would be enacted and didn't think it should be enacted.

"We don't want to see action that will proactively undermine American diplomacy," press secretary Jay Carney told reporters.

The bill would require the administration to certify Iranian compliance with the terms of the interim agreement every 30 days.

Without that certification, the legislation would re-impose all sanctions that have been eased and put in place the new restrictions. Foreign companies and banks violating the bans would be barred from doing business in the United States.

Mark Dubowitz, a sanctions advocate at the Foundation for Defense of Democracies, said the new economic penalties could cost Tehran $55 billion annually in lost exports of petroleum, fuel oil and other industrial products.

"This should be incentive enough for Iran, if it is serious about saving its economy from a deep recession, not to cheat on its nuclear commitments and to move quickly to conclude a final deal," he said.

Beyond the economic measures, the bill includes potentially contentious language requiring strong American action if Israel decides to launch a pre-emptive strike against Iran's nuclear program. Israeli Prime Minister Benjamin Netanyahu has regularly issued such threats.

"If the government of Israel is compelled to take military action in legitimate self-defense against Iran's nuclear weapon program, the United States government should stand with Israel," the bill states. It calls for "diplomatic, military and economic support" to Israel in such an eventuality.

Significantly, if 13 Democratic Senators were to support the bill, that would give the Senate an excellent chance of overriding any veto coming from the White House. But politics would almost certainly come into play, as some of those Democratic Senators would be under enormous pressure not to cut the legs off of Obama so early in his second term.

At the very least, this sends a strong message to the Iranians that at least some in Washington haven't been bamboozled by the "moderate" President Rouhani. They are going to have to demonstrate with deeds, not words, their commitment to the agreement as well as their stated desire to conduct a "peaceful" nuclear program.