By DAVID B. RIVKIN JR. And LEE A. CASEY, Jan. 20, 2015

Nuclear talks between Iran and the U.S. recommenced Jan. 14, ahead of full international talks with senior officials from the U.S., U.K., France, Russia, China and Germany two days later. A final agreement is to be reached no later than June 30. Nothing less than Middle Eastern and global security hangs in the balance.

That security depends on verifiable elimination of Iran’s nuclear-weapons and ballistic-missile programs. Unfortunately, the Obama administration is likely to accept a deal leaving in place a substantial Iranian nuclear-weapons infrastructure, including uranium-enrichment capability, long-range ballistic missiles and the ability to deploy a rudimentary nuclear force on short notice. A course correction that only Congress can effect is urgently needed.

It is difficult for Congress to stop a president determined to sign an agreement with foreign leaders. And as this newspaper pointed out in a recent editorial, President Obama has threatened to veto any legislation to impose further sanctions on Iran if the June 30 deadline is not met. Still, Tehran’s insistence that existing U.S. sanctions be lifted as part of a nuclear-weapons agreement gives U.S. lawmakers substantial leverage. The collapse of oil prices, which dealt a heavy blow to the already weakened Iranian economy, has further increased this leverage. Here is what Congress should do:

First, Congress should insist that any Iranian agreement take the form of a treaty. The Constitution requires that treaties be made only with the advice and consent of the Senate. At the time it was adopted, and throughout most of U.S. history, agreements fundamentally ordering the relationship between the U.S. and foreign nations took the form of treaties, not executive orders. A mere executive agreement, which Mr. Obama may use to evade congressional constraints here, would be constitutionally insufficient.

Iran, too, should insist on a treaty and—to ensure sanctions ultimately are lifted—on congressional involvement in the negotiations. Presidents can unilaterally terminate both executive agreements and treaties, but executive agreements carry far less weight. Presidents are more likely to revise or revoke a predecessor’s agreements or orders than they are to repudiate treaties. The Iranians have already made clear that any deal would require their parliament’s approval. It is disconcerting to see Tehran treating its legislative branch with more deference than this U.S. president is treating Congress.

Second, the entire Congress—Senate and House—should be involved. A treaty ratified by the Senate has the force and effect of law. But the current Iranian sanctions regime is so complex—having been created over decades and involving an intricate and tangled web of statutes, executive orders and implementing regulations—that only new legislation can amend or eliminate it in a manner that ensures Iranian compliance.

Presidential orders nullifying specific sanctions, such as enabling U.S. financial institutions to return to business with currently blacklisted Iranian banks, should be unacceptable to the Iranians since such actions could be reversed by President Obama’s successor. Indeed, Tehran has repeatedly expressed concern that the U.S. might not deliver on its sanctions-lifting commitments.

Third, Congress should pass legislation now clearly stating the parameters of an acceptable nuclear deal with Iran, emphasizing the need to eliminate any Iranian breakout capability. It should also put the Iranians and our allies on notice that, absent congressional approval, the president cannot deliver comprehensive and permanent relief from the existing sanctions statutes.

This would prevent the worst possible scenario: Mr. Obama makes unilateral sanctions-related commitments, on which he ultimately cannot deliver. Tehran would thus have a perfect diplomatic cover to continue its nuclear-weapons program, while casting the U.S. as the deal breaker.

The legislation should lift sanctions in stages, as Iran begins to dismantle its nuclear and ballistic-missile programs in a transparent, permanent and verifiable manner, finally complying with its own international obligations. Congress should make clear that failure to submit an agreement as a treaty will lead to the imposition of an even broader and harsher sanctions regime against Iran. The statute should impose these sanctions now, slated to go into effect by a date certain, unless Congress repeals them after reviewing the final deal with Tehran.

These standby sanctions should have no waiver provisions. Given the administration’s willful nonenforcement of other statutes it dislikes, the legislation should enable private parties to bring civil actions against sanction-busting companies and persons. They can be patterned after the private enforcement provisions in the False Claims Act, which allow private citizens to sue on behalf of the federal government.

A genuine and enforceable deal ending Iran’s nuclear programs would give the president and the United States a major foreign-policy triumph. But this is possible only with the full cooperation of Congress, which Mr. Obama needs to treat as a partner and not as an enemy to be ignored, outmaneuvered, stonewalled or steamrolled.

Messrs. Rivkin and Casey served in the Justice Department under Presidents Reagan and George H.W. Bush. They are partners in the Washington, D.C., office of Baker & Hostetler LLP. Mr. Rivkin is also a senior fellow at the Foundation for the Defense of Democracies.

Source: http://www.wsj.com/articles/david-b-rivkin-jr-and-lee-a-casey-how-congress-can-use-its-leverage-on-iran-1421800630