President Trump’s anticipated decision later today to decertify the Iran nuclear deal forces many of us to rethink what needs to come next. I had hoped that the president would agree with our major European allies of France, Germany and the United Kingdom that a side deal addressing defects of the Joint Comprehensive Plan of Action would justify keeping it. I believe that if it ain’t broke, don’t fix it.

While the deal isn’t perfect, if we withdraw, Iran could — and has said it will — withdraw too. Some fear Iran might also withdraw from the 1968 Nuclear Nonproliferation Treaty, under which 191 countries have agreed to prevent the spread of nuclear weapons and related technology. To me, that would be a major setback, and potentially provoke an arms race in the region. We would be far worse off in that scenario.

{mosads}For sure, the “transformation” that the Obama administration hoped for in our relationship with Iran has failed. Iran’s malign behavior has not improved. It has gotten worse. We should accept that fact and address those problems, with careful attention to Iranian involvement in Syria, Yemen and Lebanon. The results being tallied from the Lebanese parliamentary election suggest that Hezbollah has gained seats, and thus more influence, in that country.

There is a reason that French President Emmanuel Macron and German Chancellor Angela Merkel picked last week to visit the United States, and that British Foreign Minister Boris Johnson visited yesterday. Three of our closest allies urged the United States to stick with the JCPOA. They made clear that they are open to a four-party side agreement. The assumption is that China and Russia, the other parties to the JCPOA, would not join.

The recommendations to improve the deal — removing the expiration date, requiring inspection of military sites, putting a moratorium on ballistic missile testing, and ending Iran’s support of terror groups and operations across the Middle East region — have merit. It remains my view that addressing Iran’s meddling across the Middle East won’t get easier to manage without a deal. We still lack a comprehensive strategy to address the Iranian challenge, which also evaded the Obama administration.

What is our Plan B? Congress can’t continue to be AWOL. It needs to pass an authorization for the use of military force. The process required to enact an AUMF would also provide for a public debate on the costs and benefits of a U.S. military role. At present, our policy is tactical and episodic, relying mostly on military technology.

I also wonder if the Trump administration has adequately considered the linkage with North Korea. Obviously, the Kim regime is watching closely. By walking away from the JCPOA, we send an important message about how seriously we do or do not respect the deals to which we agree.

The contours of President Trump’s decision are not yet clear. If he waives secondary sanctions against our European allies, they will likely continue to trade with Iran and that could reduce the chance that Iran withdraws. If he doesn’t waive the secondary sanctions, then he has invited a major trade dispute with Europe, which will be amplified if he decides to impose aluminum and steel tariffs on the European Union next month.

We should not underestimate the need for our allies. The Europeans are disappointed, if not dismayed, by the U.S. decision on the Paris Climate Accord. They helped construct the world order after World War II, and we will pay a huge price if they move to align elsewhere. This is a time for Congress to step up and insist that second-degree and third-degree ramifications of these issues be considered. It is also a time to put the country first on a bipartisan basis. The stakes couldn’t be higher.

Jane Harman is president of the Woodrow Wilson International Center for Scholars. She served 16 years in Congress as a representative from California and was the ranking Democrat on the Homeland Security Intelligence Subcommittee. This column is based on her testimony on the Iran challenge today before the House Foreign Affairs Committee.