In what appears to be an egregious overstep of constitutional powers, Senate Republicans sent a letter to the Iranian government with the intent to kill any potential nuclear deal between Iran and the Obama administration – a move that makes war between Iran and the US more likely.

Forty-seven GOP Senators signed on to the “Open Letter to the Leaders of the Islamic Republic of Iran,” informing the government that “while the president negotiates international agreements, Congress plays the significant role of ratifying them,” and this current Congress—controlled by Republicans—has no intention of ever doing so.

“Anything not approved by Congress is a mere executive agreement,” the Senators, led by Sen. Tom Cotton (R-Ark.) wrote.

They added that a new president “could revoke such an agreement” and that a future Congress could “modify the terms of the agreement at any time.”

As the letter states, “President Obama will leave office January 2017, while most of us will remain in office well beyond then – perhaps decades.”

The letter was first reported on Monday, by Bloomberg’s Josh Rogin, who failed to mention that the letter contains a glaring error about constitutional procedures—namely a claim that “the Senate must ratify [a treaty] by a two-thirds vote.”

As former Assistant Attorney General Jack Goldsmith under George W. Bush pointed out on Lawfare Blog, the Senate does not ratify treaties, but instead gives the Executive Branch advice and consent. Goldsmith cites a 2001 Congressional Research Service report, which explains that, “it is the President who negotiates and ultimately ratifies treaties for the United States, but only if the Senate in the intervening period gives its advice and consent.” The distinction is important since, although Congress may indeed decline to consent to a treaty, the president, ultimately, may ratify it—a decision that a Democratic President could continue to honor in 2017.

Goldsmith admitted that this is a “technical point,” but commented, “in a letter purporting to teach a constitutional lesson, the error is embarrassing.” Particularly given that the Senators, in their outreach, claimed that Iranian leaders “may not fully understand our constitutional system.”

The letter raises more serious concerns about Congress meddling in the Executive branch’s authority to negotiate treaties. The Iranian nuclear deal has faced persistent opposition on Capitol Hill from elements of both parties. Lawmakers have vociferously spoken out against it in public, and attempted to move legislation, with the intent of making a deal political unfeasible—for example, by demanding approval of a deal, while simultaneously demanding that Iran entirely cease uranium enrichment.

Any successful effort to kill an agreement could ultimately lead to war, should either the US or Israel launch military strikes to take out Iranian enrichment facilities that would, otherwise, have most likely been monitored by international observers in any deal.

Last week’s speech to Congress by hawkish Israeli Prime Minister Benjamin Netanyahu, given at the invitation of House Speaker John Boehner (R-Ohio), was seen by the administration and more than 50 lawmakers who boycotted the speech as the most high profile attempt to sabotage negotiations.

This is not the first time in history that a Democratic president has had constitutional power to negotiate US foreign policy subverted by the GOP for political purposes.

In 1968, President Lyndon Johnson accused Richard Nixon of treason after learning that Nixon’s team was in the process of persuading the South Vietnamese to drop out of peace talks ahead of the 1968 election. Nixon believed that a prolonged war boosted his electoral chances.

“This is treason,” LBJ told then-Senate Minority Leader Everett Dirksen (R-Ill.) in a private phone call – the recording of which was released in 2008.

Those peace talks failed, and the war raged on for seven more years.

Similarly, Ronald Reagan’s election team was accused of blowing up 1980 hostage negotiations between President Jimmy Carter and the Iranian government. In what has become known as the “October Surprise Conspiracy,” evidence has shown that Reagan’s team promised the Iranians a better deal if they waited to release the hostages until after the 1980 election.