There’s a notion out there that the brewing crisis with Iran could all be settled fairly easily. All the Iranian leader has to do is send President Donald Trump a “beautiful letter,” in the manner of North Korea’s leader Kim Jong-un, and the “dotard” in the White House (as Kim once called him in tenser times) will fold, maybe even fall in love.

Or, some boast, if the situation does escalate and war breaks out, the USA will win quickly: in “two strikes—the first strike and the last strike,” as Sen. Tom Cotton, an Arkansas Republican and a known aspirant for secretary of defense, put it.

Both views reflect a blithe ignorance, of Iranian politics in the first instance and of geography, history, and the nature of warfare in the second.

First, let’s look at the Kim gambit. Trump might well buy such a letter. He seems eager for a deal, saying he’d like the Iranians to call him, even providing Swiss intermediaries with a number where he can be reached. But neither Iranian President Hassan Rouhani nor the country’s supreme leader, Ayatollah Khamenei, is inclined to send, write, or phone.

Iran is not quite a democracy, though it does have elections and factions. But it is a fairly open (if oppressive) society, certainly far more so than North Korea, which is not only an absolute dictatorship but also more hermetically sealed than any country on earth. Kim can say or do pretty much anything he wants; he can pivot on a dime and no one will complain, since grousing is punishable by death. Khamenei—who has never communicated in any way with any U.S. president—has to continue to paint America as the devil to maintain his power among the hard-line mullahs on Iran’s ruling council.

Opening negotiations with President Barack Obama’s diplomats, much less reaching an agreement that required the dismantlement of Iran’s nuclear program, was a very high risk for all involved.

The fact that Trump pulled out of the deal, even though international inspectors attested that Iran was abiding by its terms, suggests that the ayatollah won’t take a chance again, not with an American so untrustworthy. Even if he did express interest in reopening talks, perhaps because the renewed sanctions were squeezing his economy dry, he would not—could not—bring himself to pen flowery, flattering prose to the bearer of his misery.

Iran is a highly literate country—nearly everyone can read and write—and many people, especially in the cities, are plugged into the world through the internet and satellite television. If their leader wrote the sort of doting letter designed to make Trump melt, they would hear about it. Much of the regime’s legitimacy, or its rationale for oppressive policies, rests on projecting the image of threats all around—an image that Trump has done much to affirm. If suddenly Rouhani or Khamenei were seen as praising Trump (something that they did not do even to Obama—the talks with Secretary of State John Kerry were conducted on a cordial but businesslike and at times contentious basis), they would risk forfeiting their power and the foundational rhetoric of their regime.

If Trump wants to talk seriously with Rouhani or Iranian Foreign Affairs Minister Mohammad Javad Zarif, there are ways—circuitous ways, but ways nonetheless—to make this happen. If he’s looking for a new best friend, or someone who will at least pretend to be one, forget about it.

As for waging war on Iran, Cotton and others like him don’t seem to remember certain lessons of Iraq. Back in 2002–03, when President George W. Bush was preparing for the invasion, many seemingly smart people predicted a “cakewalk.” The U.S. commander, Gen. Tommy Franks, urged Bush to speed up the invasion, in March, even before the 4th Infantry Division was in place, so that his troops could come home before the peak of Iraq’s summer heat. (They ended up staying through nine summers, with 4,424 killed and more than 31,000 injured.)

Iran would be even harder than Iraq: It is 3½ times the size and has a little more than three times as many people. Its terrain is rougher and more mountainous; Iraq’s was flat and mostly clear desert. The biggest fear leading up to the invasion of Iraq was a Battle of Baghdad at the end—urban warfare with snipers firing from rooftops and alleys. It didn’t happen because Saddam Hussein fled, the police and the army disbanded, the entire ruling elite disintegrated, before the U.S. tanks arrived.

It’s true that many Iranians, especially in the cities, despise their regime. But they also loathe invaders; the memory of 1953—when the CIA and the British overthrew Mohammed Mossadegh, a popularly elected leader, and installed the shah as the West’s supine ally—remains fresh. They are not likely to welcome American soldiers as their liberators. There probably would be a Battle of Tehran, and it would likely be long and bloody.

Iran would be even harder than Iraq; it is 3½ times the size and has a little more than three times as many people.

One other big difference: Saddam had no external leverage on the invaders; his army had to fight the U.S. military head-on. Iran can wage asymmetric warfare. It could shut down the Strait of Hormuz, the waterway for more than a quarter of the world’s oil. Its proxies could launch missiles at Israel and at American forces in the region. It could also launch cyberattacks against the networks that control U.S. military communications, intelligence, and guided missiles—or, out in the wider world, America’s critical infrastructure. The U.S. also has extensive cyberoffensive capabilities, of course, but it has never used them in battle against a power with cyber forces of its own. The standoff would be unpredictable and probably very damaging to both sides.

Bush and Secretary of Defense Donald Rumsfeld sent 150,000 troops into Iraq—which proved enough to run Saddam out of town and defeat his army, but not nearly enough to stabilize things afterward. Neither of them thought “post-combat operations” would be necessary, even though their advisers warned otherwise. Now, the Pentagon has reportedly drawn up plans to send 120,000 troops to the Middle East, to deter or stave off Iranian aggression. That is but a fraction of what would be necessary if things escalated. Even Trump said that, if he did send troops to Iran, he’d send “a hell of a lot more” than 120,000.

Finally, Trump would go into war—or any other sort of pressure campaign against Iran—with none of America’s traditional allies. Saudi Arabia, the United Arab Emirates, and Israel would provide bases, intelligence support, maybe firepower (though don’t count on that). But this would leave out the European allies—who did play an important political role in the wars against Iraq—and it would accentuate the perception that this is nothing but a gang-up by Sunni Arabs, Zionists, and America against Shiites, thereby aggravating the region’s sectarian conflicts.

Different members of the administration are sending different messages about the purpose of the recent escalation. Secretary of State Mike Pompeo has sometimes depicted the campaign of “maximum pressure” as leverage to bring Iran back to the table to negotiate an improved Iran nuclear deal—though he has also said the U.S. won’t back down until Iran changes its “behavior.” National security adviser John Bolton quite openly calls for regime change, by force if necessary.

What does Trump want out of this high drama? That’s unclear. He bugged out of the Iran nuclear deal—a move that marked the genesis of this crisis—for no good reason, other than that he didn’t like it or the previous president who negotiated it. He withdrew under pressure, or with the merry blessings, of Bolton and Israeli Prime Minister Benjamin Netanyahu. If he stays passive and lets the escalation play out, he’s going to wind up in a war. If he doesn’t want a war, he should slow this juggernaut down. The problem is, he has nobody around him who seems inclined to do this. There is nobody in his administration with any experience doing diplomacy with Iran. He’s going to have to do it himself. And that, in itself, is frightening.