The revelation of a new enrichment plant in Iran has further complicated the Obama administration’s efforts to engage in diplomacy with Iran to find a nuclear fix. While there are questions as to whether Iran needed to report the plant earlier — the rules say that a Nonproliferation Treaty member state must inform the International Atomic Energy Agency 180 days before fissile material is introduced into the plant — the revelation further reduces trust between Iran and the U.N. Security Council.

Change we can believe in cannot be a ratcheting up of sanctions we don’t believe in.

While diplomacy may be a long shot, the proponents of sanctions have an even more difficult task. Unlike diplomacy, sanctions have a clear, decades-long track record of failure. In 1995, before Iran had any enrichment plants, comprehensive trade and investment sanctions were imposed on Iran to curb its nuclear activities. Nearly 15 years later, Iran’s nuclear program continues to advance. The only thing that has been curbed is the belief in sanctions as an effective stand-alone instrument to address this problem.

Indeed, few in the Obama administration have any confidence that the sanctions path will lead to a resolution to this nuclear stand-off. More likely than not, it will be a slippery slope toward a more ominous confrontation between Iran and the U.S. That is why diplomacy must be tried and exhausted, however difficult it may be.

So change we can believe in cannot be a ratcheting up of sanctions we don’t believe in.

At the same time, diplomacy limited to the nuclear issue is unlikely to succeed either. The Bush administration tended to reduce countries to a single-issue problem. In the case of Iran, it was reduced to enrichment, which just happened to be the one issue where the U.S. had the least amount of leverage.

Diplomacy with Iran will be more successful if the existing links between the nuclear issue and the other areas where Iranian behavior creates challenges for the U.S. — including Iraq, Afghanistan and Iran’s abysmal human rights record — are utilized to amass leverage rather than ignored. The U.S. has leverage as well as tangible things it can offer Iran in terms of regional security, and it can challenge Iran’s effort to question American regional leadership by addressing rather than shying away from Iran’s systematic human rights abuses.

In this search for leverage, the answer does not lie in broad-based sanctions, but in the enlargement of the agenda.

Trita Parsi is president of the National Iranian American Council and author of “Treacherous Alliances: The Secret Dealings of Israel, Iran and the United States.”