Over the last four years, the United Nations Security Council has repeatedly demanded that Iran stop producing nuclear fuel. Iran is still churning out enriched uranium and has now told United Nations inspectors that it is raising the level of enrichment  moving slightly closer to bomb-grade quality.

President Obama was right to offer to negotiate with Tehran. Washington and its allies were right to look for possible compromises even after Tehran was caught  again  hiding an enrichment plant.

Enough is enough. Iran needs to understand that its nuclear ambition comes with a very high cost.

President Obama said on Tuesday that the United States and its allies are “moving along fairly quickly” on a new sanctions resolution. He also said it would take several weeks to draft a proposal. That is not reassuring. Once a resolution is written, the negotiating process typically drags on for weeks, if not months.

Iran is in such economic and political turmoil that its government may be more vulnerable to outside pressure. Security forces have expanded a crackdown on the political opposition, arresting hundreds of people ahead of Thursday’s anniversary of the Iranian revolution.