Republicans on Wednesday were playing defense on Iran after blowback from an open letter to Tehran’s leadership signed by a majority of GOP senators.

One senator who signed the letter, John McCain (R-Ariz.), publicly admitted the letter may not have been the best way for Republicans to express their opposition to nuclear negotiations.

“What that letter did was tell the Iranians that whatever deal they make, the Congress of the United States will play a role,” he said Tuesday night on Fox News’s “On the Record with Greta van Susteren.”

“Maybe that wasn’t the best way to do that, but I think the Iranians should know that the Congress of the United States has to play a role in whether an agreement of this magnitude” is reached, McCain added.

The letter 47 Republicans sent earlier this week warning against a nuclear deal President Barack Obama is negotiating with Iran probably shouldn’t have been addressed to the regime’s leaders, said Senator Ron Johnson, who signed the letter…

“I suppose the only regret is who it’s addressed to,” Johnson said. “But the content of the letter, the fact that it was an open letter, none whatsoever,” he said in response to a question about whether Republicans regret their actions.

One-third of Republican insiders believe that Arkansas Sen. Tom Cotton and his GOP colleagues — including several potential presidential candidates — crossed the line when they published an open letter to Iranian leaders warning about a possible nuclear deal…

“The GOP letter — while sound in substance — caused the debate to shift from the administration’s wrongheadedness to the GOP’s tactics,” said a New Hampshire Republican, who — like all 92 respondents this week — completed the survey anonymously in order to speak candidly. “That’s not helpful.”

“Policy wise, the deal Obama is trying to cut is a bad one,” said another. “Politically speaking, however, the letter has been a disaster. The Democrats have totally framed and owned the debate, and our GOP senators are getting pummeled.”

First, [the substance of Cotton’s letter] cannot possibly be news to Iran. They read our newspapers, they know how our system functions. Even if the president acted with Congress’s approval, a future president with a future Congress could change the agreement. Who doesn’t know this? Nothing lasts forever, especially in politics and world affairs.

Second, we should not be sending letters to Iran, on any topic, at any time. Last November, Obama allegedly sent a secret letter asking the Ayatollah Khamenei to join us in fighting the Islamic State. And this isn’t the first time Obama has corresponded with Iran. He also sent a letter to Iran in 2009 seeking better ties. For clarity, we’re asking for better ties with a country that kills gay people by pushing them off roofs, imprisons journalists, and murders political opponents. Letters to Iran, by either party, do nothing but legitimize the backward leadership of that country. If our leadership wants to speak to Iran, it should address the Iranian people directly. This is a country held hostage by the mullahs, while we’re the leaders of the free world. Let’s act like we’ve noticed.

Third, trying to derail an Iranian agreement is a nakedly political goal, since no matter how many treaties Iran signs, there is almost no chance that they will abide by them. If a treaty is all it would take to stop Iran from having nuclear weapons, then we are in luck! Iran signed the Treaty on the Non-Proliferation of Nuclear Weapons in 1970. Since then, Iran has declared that enriching uranium is perfectly acceptable under the treaty, despite being asked by the United Nations, in 2006, to stop doing that. That was nine years ago. Are we really to believe Iran has stopped its march toward a nuke? Of course not. Obama believes in the power of his personality, but he’s dealing with a government that will lie to continue its quest for nuclear weapons. Much like President Carter was caught off guard that the Soviet Union’s Leonid Brezhnev lied to him about invading Afghanistan, it would be a sad day for America to be similarly surprised to hear that Iran does indeed have the weapons we are relying on signed papers to stop.

Dissenters have now agreed publicly that the letter was a dumb idea. Even some who signed it lament that it perhaps was an error. Cotton might have realized when Senate Foreign Relations Committee Chairman Bob Corker (R-Tenn.) said no thanks that the letter would be counterproductive, not just controversial. Corker, working to round up enough Democratic votes to override a presidential veto of legislation requiring any deal to be submitted to Congress for a 60-day review, has spoken openly about how the letter hampers his efforts. One can only imagine what he told Cotton behind closed doors…

Instead, Cotton’s snarky letter sparked a backlash not only from the president, the vice president, congressional Democrats and the foreign policy community, it shifted the debate from the substance of a deal to tactics that portray the United States as so woefully divided that its leaders are willing to circumvent and embarrass one another. The letter was especially tone-deaf because it came just days after Senate Majority Leader Mitch McConnell attempted to put Corker’s bill up for a vote — before the March 24 deadline for the framework of a deal — but pulled it after Democrats planning to vote for it accused him of using the issue for political gain…

This cheap mistake surely, in even a small way, jeopardized the odds of getting the strongest deal possible with Iran and, more importantly, making sure Iran — not the United States — shoulders the blame for failure to reach one. Heaping wrong upon wrong cannot help our efforts to prevent a nuclear Iran. The Cotton letter not only threatens the deal but our relations with the other permanent members of the United Nations Security Council that the United States is counting on to continue multilateral sanctions against Iran. It also promises to inspire the worst behavior from the left of the Democratic Party next time there is a Republican in the White House.

The White House petition calling for charges of treason against Cotton and his letter-signers has taken off, with more than enough signatures to force a response from the White House. How can it respond? Well, not by charging him with treason, which would be punishable by death, and which he didn’t commit. Sometime after this news cycle ends, Cotton can expect an official statement from the White House explaining why people should lay off…

Cotton had no enemies in his base. After the controversy is over, Cotton is likely to end up in the same position as the Democrats who attempted to undermine Ronald Reagan’s Iran negotiations—secure within the party, safe for re-election, taking advantage of bigger microphones…

“Tom Cotton’s criticism was very calm, very rational,” offered Christians United for Israel executive director David Brog in an interview. “It seems to me he knew what he was getting into. And he’s someone who knows how to make a wave, which seems to be important. All of a sudden this freshman senator has positioned himself in front of an important policy.”

It’s not often I agree with former senator and now Vice President Biden, but his words here are clear. The Senate must approve any deal President Obama negotiates with Iran by a two-thirds majority vote.

Anything less will not be considered a binding agreement when President Obama’s term expires in two years. This is true of any agreement, but in particular with the nuclear deal President Obama intends to strike with Iran…

I do not take my obligations as a senator lightly. Nor do those who are signatories to the letter. If the president won’t share our role in the process with his negotiating partner, we won’t hesitate to do it ourselves.

Our constituents elected us to the Senate, in part, to protect them from bad agreements like this and to help ensure their safety and security. And that is what we intend to do.

Forty-seven elected senators made a fact-based, substantive argument, in public, about a matter of critical importance to the national security of the United States. They did so after the Obama administration fought a bipartisan congressional push for triggered sanctions and restricted the ability of members of Congress to discuss in public the interim agreement with Iran, and after President Obama himself made clear that he would veto legislation intended to force the administration to include Congress. The administration’s position is this: Any agreement with Iran will be secret until it’s signed; congressional input is unwelcome and may be unpatriotic; and Congress will accept and abide by all terms of the deal whether its members approve or not…

Why is it imperative that Congress approve an agreement between the United States and Iraq, an emerging ally, but the president alone can finalize a deal between the United States and Iran, the world’s leading state sponsor of terrorism?

Remind us: Who is politicizing national security?

Let’s be clear about what’s happening here. The feigned outrage from the White House and its supporters is just the latest of several attempts (a) to distract from the evident shift in the Obama administration’s position on Iran—from blocking Iran’s development of nuclear weapons to managing it, (b) to silence opposition to the deal, and (c) to blame Congress for any diplomatic failure. (Obama said back in mid-January that Congress would “own” any diplomatic failure.)

An open letter to the leaders of Iran on the nuclear deal? Isn’t that a touch unseemly? A tad presumptuous? A distraction from the serious debate we’re carefully teeing up for a few weeks or months from now? And look at all those attacks on Tom Cotton! Why didn’t they listen to the cooler conservative heads and grayer Republican beards whose advice has been so helpful in the past?

If brow-furrowing were thinking, the Republican establishment would be geniuses. If hand-wringing were prudence, GOP politicians would be exemplars of Aristotelian virtue. If tongue-clucking were eloquence, conservative elites would be orators for the ages…

How do we know about Hillary Clinton’s emails—a revelation that will damage and could even derail her 2016 prospects? From the Benghazi committee headed by Trey Gowdy. Who forced the beginning of a serious debate about the full scope and meaning of the administration’s capitulation to Iran? Benjamin Netanyahu. Who stimulated a real discussion of the implications of the administration’s failure to go to Congress for approval of the Iran nuclear deal? Tom Cotton and his 46 colleagues…

In provoking the attacks on them, Gowdy, Netanyahu, and Cotton have also done a service. Used to dealing with a feckless opposition and fastidious opponents, the left has flipped out.

Are there any fans of President Obama’s foreign policy record — other than our nation’s adversaries, that is? Democrats have been noticeably quiet on the subject; Republicans have been appropriately brutal. But the president could silence critics like me and even qualify for a Profile in Courage Award by doing the right thing on Iran: Walk away from a flimsy nuclear agreement.

I say courage because signing an agreement — any agreement — would undoubtedly be a political home run. The news media would repeatedly feature the signing ceremony. The coverage would rehearse the long and tortured history between our two countries and exalt at the dawn of a new era. The Iranian pooh-bahs would appear tame and responsible. The president would look, well, presidential.An agreement would also boost the prospects for Hillary Clinton: achievement by association…

The agreements with North Korea didn’t work. And the North Korea agreements looked tougher than what we are hearing about from the Kerry negotiations: The North Korea deal required complete dismantling of the country’s enrichment capabilities and had no explicit expiration date. A soft nuclear agreement with a rogue state? Fool us twice, shame on us…

It would take uncommon courage for President Obama to scotch a deal with Iran. The Iranians undoubtedly know this, of course, which is why they have been such reluctant, resistant and effective negotiators. Turning down a weak deal may be too much to expect from a president who walked back from his own red line in Syria, but we can hope.

Ironically, the deal also likely commits the United States to future military action against Iran. Even the modest restrictions imposed will be removed in a decade, by which time Iran’s warhead and delivery mechanism will be fully operational. If, as time goes by, Washington realizes that it is unintentionally midwifing an Iranian bomb, it will have little choice but to abrogate the accord itself. Faced with the prospect of not just a nuclear-capable but also a nuclear-armed Iran, Washington may be compelled to preempt this scenario.

Moreover, the assumption of Iranian perfidy is baked into this deal. If merely a treaty-bound commitment were enough, then Iran’s longstanding membership in the Nuclear Non-Proliferation Treaty should suffice. The concept of any additional negotiations suggests, quite rightly, that Iran is likely to vitiate its own assurances. The one-year break-out time is intended to give the U.S. enough of a lead to identify Iranian cheating and marshal the international community to re-impose sanctions that will make the country heel. Hardly a chess novice, Iran would see that it has nothing to gain and everything to lose by breaking its commitments and sparking a return to the status quo ante of international isolation.

However, such a short break-out time only bolsters the likelihood of American military action. It took seven years of nuclear-related sanctions to coax Iran to the negotiating table, at which Iran has yet to make any irreversible commitments. No matter the president or Congress’ desire for alacrity, it would be impossible for even the most stringent sanctions to have their desired effect in less than twelve months. At that point, the only way the United States can prevent an Iranian break-out will be to credibly threaten the use of force. Perhaps unwittingly, the deal the Administration believes averts war only works if the U.S. is willing to go to war to enforce it.

To avoid war, the United States and Israel have two options: accept Iran as a nuclear power or negotiate a deal that eliminates Iran’s capacity to be one.

What if force is the only way to block Iran from gaining nuclear weapons? That, in fact, is probably the reality. Ideology is the raison d’etre of Iran’s regime, legitimating its rule and inspiring its leaders and their supporters. In this sense, it is akin to communist, fascist and Nazi regimes that set out to transform the world. Iran aims to carry its Islamic revolution across the Middle East and beyond. A nuclear arsenal, even if it is only brandished, would vastly enhance Iran’s power to achieve that goal.

Such visionary regimes do not trade power for a mess of foreign goods. Materialism is not their priority: They often sacrifice prosperity to adhere to ideology. Of course, they need some wealth to underwrite their power, but only a limited amount. North Korea has remained dirt poor practicing its ideology of juche, or self-reliance, but it still found the resources to build nuclear weapons…

Nonetheless, we might absorb some strikes. Wrenchingly, that might be the price of averting the heavier losses that we and others would suffer in the larger Middle Eastern conflagration that is the likely outcome of Iran’s drive to the bomb. Were Iran, which is already embroiled in Iraq, Syria, Yemen, Lebanon and Gaza, further emboldened by becoming a “nuclear threshold state,” it would probably overreach, kindling bigger wars — with Israel, Arab states or both. The United States would probably be drawn in, just as we have been in many other wars from which we had hoped to remain aloof.

Yes, there are risks to military action. But Iran’s nuclear program and vaunting ambitions have made the world a more dangerous place. Its achievement of a bomb would magnify that danger manyfold.

GOP letter to Iranian clerics undermines American leadership. No one considering running for commander-in-chief should be signing on.

— Hillary Clinton (@HillaryClinton) March 11, 2015