In his State of the Union address this week, President Obama reaffirmed his commitment to prevent a nuclear-armed Iran. He assured Congress and the nation that progress is being made through tough negotiations. He also vowed to veto any legislation—such as the sanctions bill anticipated in the Senate—that might threaten the talks.

While the politics, slogans and sound bites usually rule the day in Washington, the president reminded Congress that he doesn’t have to run for office again. Instead, his diplomatic efforts with six world powers and Iran are in pursuit of a historic opportunity to increase our national and global security without yet another war. In spite of steady diplomatic progress to deny Iran a nuclear weapon, some hardliners in Congress are seeking to scuttle any deal. Indeed, Republicans—and a few Democrats—have said they wish to pass a new sanctions bill in the coming weeks while the talks are ongoing – a risky move that experts say will most likely derail this delicate diplomatic process.

{mosads}From the facts on the ground perspective, considerable progress has been made over the past year in rolling back Iran’s nuclear program. To begin with, the interim agreement froze the program in place. Since then, Iran’s nuclear stockpile has been sharply reduced. Iran has agreed to an internationally monitored cap on the enrichment of uranium. Nuclear sites that were previously off-limits are now subject to international inspections and the frequency of inspections have been increased overall.

The diplomatic record has similarly demonstrated results. In addition to the historic interim agreement, in September 2013, presidents Obama and Rouhani had the first direct conversation between US and Iranian heads of state in 35 years. And for almost an entire year, the US and its allies have remained united with Russia and China in pursuing a diplomatic outcome while enforcing strict economic sanctions on Iran – despite the fact that these countries often have differing perspectives and international agendas.

The bottom line is that Iran is significantly further away from a nuclear weapon today than it was one year ago. What’s more, these results reflect a surprising turnabout from the preceding decade in which Iran’s capabilities grew steadily while the major powers were divided on how to respond.

Granted, the election of Rouhani has made an enormous difference. His predecessor Mahmoud Ahmadinejad staked his political career on confrontation with the West, but Ahmadinejad’s policies brought nothing but ruin to the Iranian economy. In response, Rouhani ran on a platform committed to improving relations with the West and won in a landslide. 

Though these are all very positive developments, we still have a long way to go. Decades of hostility and mistrust won’t change overnight. We’d be fools not to proceed with great caution and make sure that every aspect of any agreement is fully verifiable.

However, those who want to torpedo the critical progress that has been made are using tough talk that simply doesn’t line up with the facts.

To begin with, there are those who are demanding another round of sanctions despite the fact that neither our allies, nor our own negotiating team, nor the Russians or Chinese, support such a move.

Indeed, another round of sanctions would most likely split the international coalition that has been critical to success and principally benefit the Iranian hardliners who are most vocally opposed to Rouhani’s overtures to the West. Even more fancifully, some have argued that the US should be prepared to “force” China and Russia to support further sanctions. This may sound tough, but it is utterly implausible.

Even more unrealistic are those agitating for military strikes. Serious national security professionals understand that only a negotiated outcome is realistic. Michael Hayden, the former CIA director and NSA chief, noted that in the Bush administration, “The consensus was that [attacking Iran] would guarantee that which we are trying to prevent — an Iran that will spare nothing to build a nuclear weapon.”

As the president said last night, “There are no guarantees that negotiations will succeed, and I keep all options on the table to prevent a nuclear Iran.  But new sanctions passed by this Congress, at this moment in time, will all but guarantee that diplomacy fails–alienating America from its allies; and ensuring that Iran starts up its nuclear program again.”

We must prevent Iran from obtaining nuclear weapons. The best chance at doing so is to support the president’s challenging, but necessary, diplomatic talks that continue to make steady progress and yield verifiable results.

Johns serves on the Council for a Livable World Advisory Board and is a former deputy assistant defense secretary. Canterbury is the executive director of the nonpartisan, nonprofit Council for a Livable World and Center for Arms Control and Non-Proliferation. The views expressed are their own.