Can US afford an assault on Iran?

The US-Iran standoff continues to evolve quickly, yet commentaries covering tanker attacks, a downed drone, and reversed orders for airstrikes from the White House fail to explain the logic behind an intervention, if the Trump administration decides to intervene. Therefore, it is worth exploring what a war between the two would actually look like.

Ideally, the US should have learnt some lessons from Vietnam, Afghanistan and Iraq wars. Distant foreign conflicts are difficult to win, which most of the Americans are usually unwilling to think unless faced with a massive and immediate threat. Small-scale engagements accomplish little and are instead more likely to evolve into larger conflicts. Installing foreign governments are more difficult, costly, time-consuming and even deadly than leaders are likely to claim.

Backing a local proxy is often unpalatable for the country’s sense of ethics, but US adversaries often have no such misgivings. Those proxies are often an ineffective substitute for a US military presence when it comes to pursuing the US agenda. Without a substantial, long-term commitment of US forces, such wars are more likely to leave a power vacuum when the US withdraws. The outcomes are collapsed government, invasion by a neighbor, revolution that creates new and uncertain structures – or some combination of all these. In fact, the US has had a few true victories in the wars it has fought since World War II.

Airstrikes

Exploring US government’s options in a war with Iran, the most probable option is limited strikes, similar in scale to or perhaps somewhat greater than the strikes on Syria that the Trump administration ordered on Syria in 2017 and 2018. But Iran is not Syria, as it has a sophisticated air defense infrastructure and plenty of air denial capability, increasing the chance of US casualties. Further, a limited air strike probably wouldn’t accomplish anything meaningful. It might take out a handful of radar and air defense installations, sending a political signal but affecting in no real way the strategic reality on the ground. The only time US air power alone has significantly shifted the reality on the ground was in Kosovo, but Iran today is far more powerful than Serbia in 1999.

On the contrary, limited strikes may have opposite outcome. Iran’s economy is hurting and its society appears more divided as citizens continue to grow frustrated with the government. The US has imposed sanctions as a strategy to hobble the economy enough to create social pressure on Tehran, forcing the government to spend less on its defenses and funding of militias in Syria and Iraq, so far, they’ve been effective. If the US continues this tactic, over time Iran’s domestic situation would worsen, and its citizens would be more likely to blame its leadership for their problems. And that would likely intensify the divisions within the government that are already emerging, resulting in either a more Western-friendly government or one dominated by the Islamic Revolutionary Guard Corps.

Even limited US airstrikes would increase the probability of the IRGC consolidating power. If the sanctions can help create division, an attack would unite Iran’s hard-liners and reformers against the US. That unity would likely occur under the aegis of the hard-liners who have been warning all along that this day would come if Iran were foolish enough to trust the US. As the most powerful entity in the county, the IRGC would probably take over, and do so with popular support.

Use of Ground Force

Ground force is a less likely choice for the US, even with limited objectives (like eliminating specific military equipment or securing passage through the Strait of Hormuz). But it would be more likely to achieve what the US really wants, Iran to recall its foreign militias to defend the home. But when a military force is rapidly removed without a replacement ready to take its place, it creates a power vacuum and, therefore, an opportunity for others to fill the void. The pace at which Iran withdraws its militias from Syria and Iraq can alter the regional balance of power.

If any militant group occupies the space vacated by Iran, US would have to again deal with this problem, which would require reoccupying parts of Iraq while fighting Iran. This would likely entail support from Syrian and Iraqi Kurdish forces, which would again put pressure on US-Turkey relations. But the Syrian Kurds may not see a long-term alliance with the US as in its best interest after the US threatened to leave them high and dry in December 2018. They could instead seek out a political resolution with Damascus, backed by Russia that would protect them from Turkey. It is also likely that Russia may step in to back Kurdish groups such as the Syrian Democratic Forces to fight back. But that would mean the US would be depending on Russian assistance to cover its western flank, and in exchange for such cooperation Russia would likely demand US concessions in places like Ukraine. In short, going all-in with Iran would require either a large-scale US occupation or dependence on Russia in Syria and Iraq. Neither of those are appealing options for Washington.

Regime Change

If it is regime change that the US may attempt in Iran, the risks are even greater. The fallout would look much like that of the second Iraq war, but on a far greater scale. Installing a pro-American regime isn’t easy, but it can easily fail. The US would have to commit to an indefinite occupation of Iran or again risk the emergence of a power vacuum. The US would have to deal with the rest of the Middle East. In the best-case scenario, the US would install a new head of government while facing a lengthy insurgency, which would likely include the vestiges of the IRGC and its heavy weaponry. After a long, costly occupation, the US would have to withdraw, leaving Iran’s leaders to face opposition on their own. The half-life of US-installed leaders in the Middle East would not be long. Limited airstrikes or a full-scale invasion (military confrontation with Iran) would create more problems for the US rather than offering any sustainable solution.