More than 200 retired U.S. generals and admirals added their names to the Iran nuclear agreement’s opposition this week after they sent a letter to top congressional leaders pressing lawmakers to reject the accord.

The former senior military officers contend that the deal threatens U.S. national security, noting the estimated $150 billion that will pour into Tehran if sanctions are lifted and will provide the regime with more funds to support terrorism.

The letter also points to limitations of international inspections, claiming that the current framework is unverifiable and lacks credibility.

The retired officers also say the agreement does not prevent Iran from acquiring a nuclear weapon, but instead provides a “legitimate path” toward its nuclear ambitions.

“This agreement will enable Iran to become far more dangerous, render the Mideast still more unstable and introduce new threats to American interests as well as our allies,” they wrote.

The former officers sent the letter to Republican and Democratic leaders in the House and Senate in response to one sent last week from nearly 40 retired generals and admirals endorsing the deal.

They wrote that the agreement among Iran, the U.S., and five other nations is the “most effective means” to preventing Tehran from acquiring nuclear weapons and “strengthens” U.S. national security.

“If the deal is rejected by America, the Iranians could have a nuclear weapon within a year. The choice is that stark.”

Congress has until Sept. 17 to accept or reject the deal.