Among the many unintended--and disastrous--consequences of President Bush's war in Iraq was to replace the Sunni dictator in Baghdad with a sectarian Shiite government whose closest ally was naturally Iran. So, it was only common sense that President Obama would send a letter to the Supreme Leader Ayatollah Ali Khamenei in Tehran regarding the ISIS threat that both U.S. and Iranian forces were already combatting in Iraq. Needless to say, Republicans are apoplectic. As Sarah Palin put it in her latest jihad against the English language, President Obama's letter shows he is "willing to negotiate with terrorists" and was "an anti-Reagan move."
Here's a newsflash for Sarah Palin, John McCain, Mitt Romney and their ilk. Barack Obama only sent Iran a letter. Ronald Reagan sent a cake, a Bible and U.S. weapons.
Of course, you'd never know that from Palin's rant, "President Palling Around with Terrorists":

Good God, Mr. President. To partner with Iran is to trust the enemy, which is insane. Iran has complicity in the rise of ISIS as it supports radical militias and arms Islamic terrorists...
In the 2008 campaign Sen. McCain and I warned, on behalf of every reasonable person, that your willingness to negotiate with terrorists would get Americans killed; that pulling an anti-Reagan move by taking our Big Stick of strength and putting it in the hands of any foe could be insurmountably devastating for our allies.

Leave aside for the moment that Iran has sent units of its Revolutionary Guard to protect Baghdad from Islamic State fighters, extremist Sunni forces who also happen to pose a threat to Tehran's Alawite client in Syria, Bashar Al-Assad. As the record shows, the "Reagan move" would be for the United States to try to buy the cooperation of Iran and its Hezbollah proxies with American blood on their hands by shipping U.S. arms to Tehran.
The Iran-Contra scandal, as you'll recall, almost laid waste to the Reagan presidency. Desperate to free U.S. hostages held by Iranian proxies in Lebanon, President Reagan provided weapons Tehran badly needed in its long war with Saddam Hussein (who, of course, was backed by the United States). In a clumsy and illegal attempt to skirt U.S. law, the proceeds of those sales were then funneled to the contras fighting the Sandinistas in Nicaragua. And as the New York Times recalled, Reagan's fiasco started with an emissary bearing gifts from the Gipper himself:

A retired Central Intelligence Agency official has confirmed to the Senate Intelligence Committee that on the secret mission to Teheran last May, Robert C. McFarlane and his party carried a Bible with a handwritten verse from President Reagan for Iranian leaders.
According to a person who has read the committee's draft report, the retired C.I.A. official, George W. Cave, an Iran expert who was part of the mission, said the group had 10 falsified passports, believed to be Irish, and a key-shaped cake to symbolize the anticipated ''opening'' to Iran.

As his diaries published in 2005 show, President Ronald Reagan was under no illusions about either the illegality of the scheme or that it constituted anything other than a swap of arms for hostages. On Thursday, December 5, 1985, Reagan wrote in his diary:

N.S.C. briefing--probably Bud's last. Subject was our undercover effort to free our 5 hostages held by terrorists in Lebanon. It is a complex undertaking with only a few of us in on it. I won't even write in the diary what we're up to.

Nevertheless, just two days later the Gipper wrote about that very topic. On Saturday, December 7, Reagan noted in his diary:

Day opened with "Rex" (our new dog) on our bed. I then had a meeting with Don R., Cap W. and Bud M., John P., Geo. Schultz and Mahan of C.I.A. This had to do with the complex plan which could return our 5 hostages & help some officials in Iran who want to turn that country from its present course & on to a better relationship with us. It calls for Israel selling some weapons to Iran. As they are delivered in installments by air our hostages will be released. The weapons will go to the moderate leaders in the army who are essential if there is to be a change to a more stable govt. We then sell Israel replacements for the delivered weapons. None of this is a gift--the Iranians pay cash for the weapons--so does Israel.
George S. Cap and Don are opposed--Cong. has imposed a law that we can't sell Iran weapons or sell any other country weapons for resale to Iran. Geo. also thinks this violates our policy of not paying off terrorists. I claim the weapons are for those who want to change the govt of Iran & no ransom is being pd. for the hostages. No direct sale would be made by us to Iran but we would be replacing the weapons sold by Israel.

In case there was any doubt that Ronald Reagan blessed the delivery of hundreds of advanced anti-tank weapons to Tehran, the President himself removed it with his January 17, 1986 diary entry, "I agreed to sell TOWs to Iran."
The rest, as they say, is history. Or more accurately, rewritten history. As President Reagan told the American people in a nationally televised address on March 4, 1987:

"A few months ago I told the American people I did not trade arms for hostages. My heart and my best intentions still tell me that's true, but the facts and the evidence tell me it is not. As the Tower board reported, what began as a strategic opening to Iran deteriorated, in its implementation, into trading arms for hostages."

Of course, the pathetic saga didn't end there. Then Lt. Colonel and now Fox News commentator Oliver North saw his Iran-Contra conviction overturned by an appellate court led by faithful Republican partisan and later Iraq WMD commissioner Laurence Silberman. And in December 1992, outgoing President George H.W. Bush offered Christmas pardons to Defense Secretary Caspar Weinberger and five other Iran-Contra scandal figures. Among them were John Poindexter and Elliott Abrams, men who eight years later reprised their roles in the administration of George W. Bush. (As it turns out, Abrams--one of the people who brought you the Iraq War--also served as an adviser for Mitt Romney during the 2012 presidential campaign. In that capacity, he argued that Congress should give the President the authorization to use force against Iran for a preventive war to destroy Tehran's nuclear program.)
Nevertheless, Republicans are once again furious at Barack Obama's handling of America's Iran policy. During the 2012 campaign, Mitt Romney forgot about Iran-Contra altogether, declaring, "Ronald Reagan made it crystal clear that the Iranians would pay a very stiff price for continuing their criminal behavior" and that the right course toward Tehran's nuclear program was "what Ronald Reagan called 'peace through strength.'" In June, 2016 White House hopeful Ted Cruz (R-TX) protested the trade that freed U.S. Army soldier Bowe Bergdahl, "What does this tell the terrorists, that if you capture a U.S. soldier you can trade that soldier for five terrorists?" Then again, back in January Senator Cruz tweeted a front page picture of Ronald Reagan's first inauguration with the message:

"Now there is a man who knew how to deal with the Iranians."

Five months after Cruz' historical revisionism, Sarah Palin added her own as she spoke for her 4.5 million Facebook followers when she said:

What is wrong with you, Barack Obama? You cannot pal around with terrorists and expect us to survive.

Of course, her Fox News colleague Oliver North didn't just survive, he prospered from palling around with terrorists. As for those U.S. weapons the Gipper delivered to Iran even after the Beirut Marine barracks bombing and the executions of American prisoners held by Hezbollah in Lebanon, the Reagan Library probably has the receipts.