A GOP letter from Senate Republicans to Iran about the pending nuclear deal warns Iranian leaders that any agreement between Washington and Tehran could be voided by Congress and simply not upheld once Obama leaves the White House in 2017.  The letter was spearheaded by Sen. Tom Cotton (R-Ark.).

Naturally, it received some backlash.  White House press secretary Josh Earnest was unusually blunt in ripping the Senate GOP, saying “it’s surprising to me there are some Republican senators who are seeking to establish a backchannel with hardliners in Iran to undermine an agreement with Iran and the international community.”

Earnest said Republicans have a “long and rather sordid history” of putting military options ahead of diplomatic ones, and called the letter, signed by 47 GOP lawmakers, “the continuation of a partisan strategy to undermine the president’s authority.”

It’s not just the president, the vice president, and fellow Senate Republicans appalled at the open letter to Iran. The New York Daily News, for instance, endorsed Mitt Romney in 2012, but ran the cover you can see at the left.

The Wall Street Journal is … the Wall Street Journal, but it editorialized that “The problem with the GOP letter is that it’s a distraction from what should be the main political goal of persuading the American people.”

But it’s worth remembering that, for Tom Cotton at least, this letter wasn’t the first step off the deep end on Iran. In 2013, Cotton offered an amendment that would have harshly punished people violating sanctions on Iran. Actually, Cotton wouldn’t have stopped at harshly punishing the violators themselves.

Cotton also seeks to punish any family member of those people, “to include a spouse and any relative to the third degree,” including, “parents, children, aunts, uncles, nephews, nieces, grandparents, great grandparents, grandkids, great grandkids,” Cotton said.

Yes, Cotton thinks that the great grandchildren of people who violate Iran sanctions should be imprisoned. Which, by the way, is completely unconstitutional. But this is someone who got the vast majority of his Republican colleagues in the Senate, including leadership, to sign onto a letter to Iran trying to torpedo American diplomacy. Congressional Republicans listen to this man. That’s terrifying—but if this open letter has helped discredit him publicly, it may be one good outcome of the whole mess.

Perhaps my favorite criticism comes from Iran itself. Asked about the open letter, the Iranian Foreign Minister, Dr. Javad Zarif, responded that “in our view, this letter has no legal value and is mostly a propaganda ploy. It is very interesting that while negotiations are still in progress and while no agreement has been reached, some political pressure groups are so afraid even of the prospect of an agreement that they resort to unconventional methods, unprecedented in diplomatic history. This indicates that like Netanyahu, who considers peace as an existential threat, some are opposed to any agreement, regardless of its content.”Zarif expressed astonishment that some members of US Congress find it appropriate to write to leaders of another country against their own President and administration.

He pointed out that from reading the open letter, it seems that the authors not only do not understand international law, but are not fully cognizant of the nuances of their own Constitution when it comes to presidential powers in the conduct of foreign policy.Foreign Minister Zarif added that “I should bring one important point to the attention of the authors and that is, the world is not the United States, and the conduct of inter-state relations is governed by international law, and not by US domestic law. The authors may not fully understand that in international law, governments represent the entirety of their respective states, are responsible for the conduct of foreign affairs, are required to fulfil the obligations they undertake with other states and may not invoke their internal law as justification for failure to perform their international obligations.”The Iranian Foreign Minister added that “Change of administration does not in any way relieve the next administration from international obligations undertaken by its predecessor in a possible agreement about Iran`s peaceful nuclear program.” He continued “I wish to enlighten the authors that if the next administration revokes any agreement with the stroke of a pen, as they boast, it will have simply committed a blatant violation of international law.He emphasized that if the current negotiation with P5+1 result in a Joint Comprehensive Plan of Action, it will not be a bilateral agreement between Iran and the US, but rather one that will be concluded with the participation of five other countries, including all permanent members of the Security Council, and will also be endorsed by a Security Council resolution.

Zarif expressed the hope that his comments “may enrich the knowledge of the authors to recognize that according to international law, Congress may not modify the terms of the agreement at any time as they claim, and if Congress adopts any measure to impede its implementation, it will have committed a material breach of US obligations.”

The Foreign Minister also informed the authors that majority of US international agreements in recent decades are in fact what the signatories describe as “mere executive agreements” and not treaties ratified by the Senate.

He reminded them that “their letter in fact undermines the credibility of thousands of such mere executive agreements that have been or will be entered into by the US with various other governments.

Zarif concluded by stating that “the Islamic Republic of Iran has entered these negotiations in good faith and with the political will to reach an agreement, and it is imperative for our counterparts to prove similar good faith and political will in order to make an agreement possible.”

He’s right about all that of course.  What’s particularly odd about the letter is that the reasoning there would apply to ANY international treaty, not just the current one being negotiated.  Basically, Republicans are hanging out a sign to ALL countries saying, “Don’t enter into any treaties or trade agreements of anything like that with the current president, because we Republicans might not honor it”.

Scary.