The recent Syrian chemical weapons deal no one thought possible proves the value of not closing off options.  There is a difference between healthy skepticism with Iran and a dangerous dismissiveness that would commit us to either a nuclear armed Iran or an incredibly costly and dangerous regional war.

The dynamics of change in Tehran started with Mahmoud Ahmadinejad’s departure and the election of Hassan Rouhani, Iran’s newly-inaugurated moderate president. Rouhani campaigned in part on working with the West to restore Iran’s standing in the world and to find a negotiated settlement to the nuclear issue. Rouhani has already begun acting on his campaign promises by appointing a U.S. educated foreign minister and nuclear negotiator, condemning the use of chemical weapons in Syria, and most recently, speaking with President Obama by phone.

It is smart to view Rouhani’s actions with a healthy dose of skepticism, but skepticism and dismissiveness are not the same thing. To snub Rouhani’s initial overtures—as some on the Hill are demanding--would close a door on the possibility of a negotiated solution to Iran’s nuclear program, a solution that is by far the best outcome for America’s national security and global interests.

We cannot respond to Iran’s recent elections and the first outreach by an Iranian leader in 30 years with new sanctions against Iran.  Additional sanctions now would weaken Rouhani’s hand domestically, make it harder to win concessions from Iran at the negotiating table, and fuel hardliners in Tehran who say that the United States cannot be trusted and will never accept a deal. This must be avoided at all costs. While few in Congress have been acting like statesmen recently, everyone knows you don’t start a negotiation by slapping your counterpart in the face as he extends his hand.

A negotiated solution is the only realistic avenue to achieve America’s long-term security goals in the region. For years commanders in the field have warned that war with Iran would come at enormous cost and be counter to our interests in the region. Iran has not yet made the decision to build a nuclear weapon and to move preemptively to strike is the surest way to ensure the regime will pursue a weapon for self-defense. Intelligence assessments from our allies agree, and Meir Dagan, the former Chief of Mossad said that attacking Iran “would mean regional war, and in that case you would have given Iran the best possible reason to continue the nuclear program.”

Critics characterize the diplomatic efforts from Iran as all show.  And there is no question that Iran is a state pursuing its own interests.  Those interests have--and often will--run counter to our interests. No new president in Tehran--a reformer or not--will be able to alter those dynamics entirely.

But we must also remember that diplomacy is not something done between friends.  It is done between adversaries. While healthy skepticism is prudent in forthcoming discussions with Iran, we are negotiating from a position of strength.  We can focus on a deal of intrusive, verifiable inspections on a peaceful Iranian nuclear energy program in exchange for sanctions relief that would lock in American security interests in the region for decades.

The upcoming negotiations with Iran will not be easy. But America has never backed away from finishing a job just because it was too challenging.  Sen. Robert MenendezRobert (Bob) MenendezCongress must provide flexible funding for owners of repeatedly flooded properties Senate ethics panel resumes Menendez probe after judge declares mistrial Judge declares mistrial in Menendez bribery case MORE (D-N.J.) has been a leader on Iran in the past.  He needs to continue to lead by working with his colleagues to delay the introduction and implementation of new sanctions that risk imperiling America’s best diplomatic efforts to assure Iran does not develop a nuclear weapon.

Buskirk served in the National Guard from 1978 to 2004.