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Which Path to Persia? Options for a New American Strategy toward Iran

In June 2009 the Saban Center for Middle East Policy at the Brookings Institution, a Washington research center, issued an analysis paper, Which Path to Persia? Options for a New American Strategy toward Iran. The authors named on the paper are Kenneth M. Pollack, Daniel L. Byman, Martin Indyk, Suzanne Maloney, Michael E. O'Hanlon, and Bruce Riedel. Pollack is also named as the editor. The link above is an Internet Archive text copy. The archive item carries a different title on the wrapper. The text inside is the Brookings paper. An American family should care because the invasion chapter estimates hundreds of thousands of U.S. troops to reach Tehran, about 1.4 million to occupy Iran, and says a long occupation might require a draft. Selective Service is the U.S. system that keeps a roster of young men who can be ordered into the military. The paper is a 2009 menu of options.

Evidence rating: MODERATE. The rating covers the invasion chapter of Brookings's Saban Center paper Which Path to Persia?, June 2009: 200,000 to 250,000 troops to invade, 1.4 million to occupy, and, in the authors' words as summarized here, some form of partial conscription if the force had to be raised. The paper lays out several options without choosing one.

What the article says

The paper's table of contents sorts options into diplomacy, military action, regime change, and containment. Chapter 3 is titled "Going All the Way: Invasion." The chapter opens by saying there is little appetite in the United States for another Middle East war, that American ground forces are already overstretched, and that an invasion would require calling up huge numbers of National Guard and reserve personnel for several years.

The authors write that an initial invasion force might be comparable to the 2003 Iraq war, about 200,000 Western personnel. For Iran they add terrain and insurgency. They write that the force would probably include two to four Marine regimental combat teams, about 15,000 to 30,000 Marines, to seize a beachhead and a major port. They add airmobile brigades, naming the 101st Air Assault Division, the 82nd Airborne Division, and possibly the 173rd Airborne Brigade, to get through the mountains. They add at least one and possibly three heavy armored divisions for the drive on Tehran.

Again, this suggests a force roughly comparable to that employed for Operation Iraqi Freedom: four to six divisions amounting to 200,000 to 250,000 troops.

The authors of Which Path to Persia?, Saban Center at the Brookings Institution, Analysis Paper Number 20, June 2009, in the chapter "Going All the Way: Invasion."

They write that if neighbors gave little help, the Navy would have to carry the logistics, and Iran would try to close the Strait of Hormuz to stop a landing. They say U.S. air and sea power could crush Iran's air and sea defenses in weeks, but that this would take a major commitment, including three or more aircraft carriers if nearby airfields were unavailable.

They then say the occupation would dwarf the invasion. They cite scholars who suggest about 20 security personnel per 1,000 people to protect civilians after a war.

This ratio suggests that an occupation force of 1.4 million troops would be needed for Iran.

The same chapter, June 2009.

They write that a high-quality force might cut that number in half, and that half would still be essentially the entire active-duty Army and Marine Corps. Even a best case, they write, would mean keeping 100,000 to 200,000 U.S. troops in Iran for several years, plus commitments in Iraq and Afghanistan. They write that only a major, rapid increase in the armed forces could do that without wrecking the National Guard and reserve, and that such an increase might require some form of partial conscription. They write that most Iranians would fiercely oppose a U.S. invasion even if many wanted their regime gone. In the political section they write that, in worst-case scenarios, the president might even need to ask the American people to accept some form of limited conscription. In the list of disadvantages they repeat that the option might require partial conscription for some period and a greater expansion of ground forces than at any time since the Second World War.

They also list what they call advantages: destroying the nuclear program, removing the regime, and acting under American control. They write that if the president had overwhelming public support, invasion would be a viable option, and that without it the occupation would likely be mismanaged.

What other reporting and posts add

The chapter people quote in 2026 is not the invasion chapter. Posts about this war most often cite chapter 5, titled "Leave it to Bibi" (Bibi is Benjamin Netanyahu's nickname), which discussed letting Israel strike Iran. One reader quoted it on 26 September 2026: "the United States would encourage—and perhaps even assist—the Israelis in conducting the strikes themselves, in the expectation that both international criticism and Iranian retaliation would be deflected away from the United States and onto Israel." @Greg_the_Berean, 26 September 2026. (capture: twitter/t13__v148.md) Commentator Brian Berletic had argued since 2024 that later events followed this paper; his framing is his own reading. @BrianJBerletic, 9 April 2024. (capture: twitter/t17__v196.md) Note the division of labor in that chapter: Israel strikes, America stays back. It is the opposite of the 2026 fear that Americans would supply the ground troops.

The invasion numbers, measured against 2026. The paper's 200,000 to 250,000 to invade and 1.4 million to occupy are far above anything reported in 2026, when a Senate resolution put total US deployment to the region at "more than 50,000" (S.J.Res. 211; capture: twitter/t52__v622.md). They match the scale of later outside estimates, such as a Jerusalem Post column's "750 thousand and 1.5 million" (a035; capture: twitter/t14__v161.md).

What it shows

Seventeen years before the war, a Brookings study written for Washington's policy class sized an American invasion of Iran in detail: Marines to seize a beachhead and a port, the 82nd and 101st Airborne through the mountains, armored divisions for the drive on Tehran, and an occupation force of 1.4 million, which the authors said could require the President to ask Americans to accept some form of limited conscription. The same paper's chapter "Leave it to Bibi" described letting Israel strike first so that retaliation would be "deflected away from the United States and onto Israel."

The units it named, Marines and the 82nd Airborne, are the ones sent toward Iran in March 2026. See Force-Planning Documents and The Buildup.

Check it yourself

Internet Archive text of Which Path to Persia?, Saban Center Analysis Paper Number 20, June 2009. The archive wrapper uses another title. The paper text is the Brookings study.

Brookings book page for Which Path to Persia?, release date 13 July 2009. That page names the same six authors and says they do not argue for one approach over another. It does not reprint the troop figures. Those figures are in the archive text of the paper.

Why a 2009 study matters now: the Brookings Institution is a large, centrist Washington think tank, and its Saban Center (named for donor Haim Saban) focused on the Middle East. This paper, written seventeen years before the United States and Israel began bombing Iran on 28 February 2026, set out every option for dealing with Iran, including a full invasion. Its authors included future senior officials and analysts who are still writing about this war in 2026, among them Kenneth Pollack (a197) and Michael O'Hanlon (a196, a198). Its invasion chapter is one of the few public estimates of what occupying Iran would take.

Research captures: twitter/t13__v148.md, twitter/t17__v196.md, twitter/t52__v622.md, twitter/t14__v161.md

Last Updated: 2026-09-26