Trump's assassination of Soleimani is a shocking use of a leader 'decapitation' strategy that has rarely worked in the past

• The drone strike that killed Iran's top general, Qassem Soleimani, was the most shocking example of the US employing the leader "decapitation" strategy since World War II.
• Jeffrey Feltman, the former US ambassador to Lebanon, told Insider that it's important to "keep in mind that, even given years of US-Iranian hostilities, killing Soleimani is something new."
• Decapitation strikes generally only offer short-term gains while failing to address root problems. In many cases, such strikes create more problems than they solve.
• "One way you can say it's clear that this decapitation strike is a problem is the fact it makes it harder for the Americans to fight ISIS in the region," Ian Bremmer, president and founder of Eurasia Group, told Insider.
• Visit Business Insider's homepage for more stories.

President Donald Trump's order to kill Iran's most important military leader, Maj. Gen. Qassem Soleimani, was the most significant example of the US employing the leader "decapitation" strategy in over half a century - a move that sent shockwaves across the region.

Though the US and Iran have been adversaries for roughly four decades, neither side has assassinated a senior military leader in such a brazen and public way before.

Jeffrey Feltman, the former US ambassador to Lebanon, told Insider that it's important to "keep in mind that, even given years of US-Iranian hostilities, killing Soleimani is something new."

The US has killed the leaders of terror groups before, most recently the Oct. 26 death of ISIS' leader. But the last time the US took out a military leader of Soleimani's magnitude in a foreign country was during World War II, by targeting the Imperial Japanese admiral who planned the surprise attack on Pearl Harbor, Hawaii in 1941.

"This was probably the most major decapitation strike that the US has really ever been involved with since they killed Admiral [Isoroku] Yamamoto during World War II," Phillip Smyth, an expert on Shiite Islamist militarism and senior fellow at the Washington Institute, told Insider of the drone strike that killed Soleimani.

Decapitation strikes - military attacks meant to debilitate by targeting and killing leadership - have shown mixed results for the US over the years. More often than not, they serve as a short-term propaganda boost and morale victory while either exacerbating or failing to stop an ideological opponent that can quickly select new leaders and still has the trained forces ready for missions.

Soleimani's killing may be no exception. The supreme leader named a new Quds Force commander on the day of his death and there are no signs the networks to terror groups and militias that Soleimani built is collapsing, according to many regional experts and former US diplomats and officials. They noted the ripple effect of his assassination has already caused problems in the ISIS fight and for the future of US troops in Iraq.

'We're going to continue to be in a very confrontational situation'

In less than a week, Soleimani's death resulted in a retaliatory missile attack from Iran against US and coalition forces in Iraq. The incident led to no US casualties and Iran subsequently offered Trump an off-ramp away from a wider war, which he accepted.

Iran and the US have, for the moment, avoided a direct conflict. But that does not mean they are at peace, nor does it eliminate decades of hostilities and or the potential for ongoing consequences from the decapitation strike.

"We're going to continue to be in a very confrontational situation," former NATO commander Adm. James Stavridis said on Wednesday after Trump gave a speech signaling the US would not respond to Iran's missile attack.

The convoluted array of forces converging upon the Middle East also mean it's a region in which an attack on one group can at times serve to the advantage of another.

"One way you can say it's clear that this decapitation strike is a problem is the fact it makes it harder for the Americans to fight ISIS in the region," Ian Bremmer, president and founder of Eurasia Group, told Insider.

Amid concerns over potential attacks from Iran-backed Shia militias, the US has suspended anti-ISIS operations in the wake the Soleimani strike. Correspondingly, NATO, which has been training Iraqi soldiers fighting ISIS, has reduced its presence in Iraq in recent days.

And after three years of insults from Trump, there's also the issue of US allies not showing support for this move.

"The US has a much weaker relationship with allies across the region and in Europe than we did before - and that's a real problem," Bremmer said.

Much of this is linked to Trump's decision to withdraw from the 2015 nuclear deal with Iran and not necessarily directly tied to Soleimani's assassination, but his killing seems to be contributing to a growing rift.

"The French should be with us. They're not," Bremmer said. "The Europeans aren't with us...because we pulled out of the Iranian nuclear deal against all of their interests, by ourself, and that's what created all the escalation to begin with."

'A charismatic leader'

With so many risks involved, Soleimani's killing immediately raised questions among Iran watchers as to whether Trump considered the ramifications of taking him out - or if it was just another example of his impulsivity taking the wheel.

The Trump administration has justified Soleimani's killing by pointing to his malign activities across the Middle East, while claiming there's intelligence suggesting he posed an "imminent" threat to the US, without providing clear evidence to support the latter assertion.

Soleimani was the leader of the Iranian Revolutionary Guard Corps' (IRGC) elite and secretive Quds force, handling Iran's external operations and charged with spreading the Islamic revolution beyond its borders.

What that meant in reality was that Soleimani built a network of militias that wreaked havoc on Iran's behalf across the Middle East. The Trump administration designated the IRGC as a terrorist organization, and has referred to Soleimani - who was linked to the deaths of at least 608 US service members in Iraq - as a terrorist.

While the US saw him as a terrorist, Soleimani was an almost mythic figure in the Middle East and widely considered the second most important leader in Iran after Iranian Supreme Leader Ayatollah Ali Khamenei.

Bremmer described Soleimani as a "singular force" who "does matter," pointing to his charisma, reputation, and the network he built up with "a bunch of rag-tag, ideologically-only-somewhat-aligned groups from Yemen to Gaza to Lebanon to Iraq to Syria."

Similarly, Smyth said: "He was a charismatic leader who followed through on trying to achieve the Islamic revolution's ends in the region...His personality was very important."

Smyth, who has been researching Shia militias for over 10 years and sometimes communicates with them, said these groups are really shaken up by Soleimani's death.

"They did not expect this...This really sent a message," Smyth said, adding that while the threats to American assets following Soleimani's death have increased, the Iranian general also posed a major threat and is not easily replaceable.

"When you talk to people in the Middle East, particularly Shia militia people, seeing their reaction said it at all to me," Smyth said, "They were thrown on their backs and this was a shock for them, and now there's going to have to be a lot of reassessment in Tehran."

Soleimani's replacement, Esmail Ghaani, is "not as charismatic," Smyth went on to say, and killing Soleimani sets a red line and sends a clear message that "if you kill an American...there will be some very, very harsh repercussions for that." The strike that took out Soleimani came not long after an American contractor was killed in a rocket attack carried out by an Iran-backed Shia militia in late December.

Similarly, Bremmer said that on top of crippling economic sanctions imposed by the Trump administration, Soleimani's killing weakens Iran's "terror network."

"All of that means more limited capacity to engage on strikes against Americans," Bremmer added.

'Iran is not losing control of its militias'

But it would also be misleading to suggest that Soleimani's death has dismantled or disabled the vast network of militias Iran has built up across the region.

"Iran is not losing control of its militias - just because you do a decapitation strike, it doesn't necessarily mean that these groups are going to fly off on their own," Smyth said, citing the loyalty Soleimani and his lieutenants secured among these groups.

These groups do have some level of agency, but they also know who they're reporting back to, who they're ideologically loyal to, and where they get arms and funding from, Smyth said, alluding to the IRGC.

When it comes to the impact of decapitation strikes, Feltman said it's important to look at "the organization that has been decapitated as well as the leadership qualities of the headless corpse and his successor."

Feltman pointed to the example of Osama bin Laden, the Al Qaeda founder who was killed in 2011 under the Obama administration.

"Without question, Al Qaeda is seriously weakened without the leadership of Osama bin Laden," and his replacement, Ayman al-Zawahiri, does not "play the same role," the former US ambassador said. Zawahiri has frequently been described by US officials and analysts as not nearly as charismatic or effective at leadership as bin Laden.

"In the case of the Quds Force, I do not believe that Soleimani was the single point of failure. We don't know if Esmail Qaani can replicate Soleimani's diabolical star power, but the Quds Force is sufficiently advanced as an institution to survive intact," Feltman said. "In short, decapitation may work in a personality-based organization but not when there is a strong institution with layers of leadership hierarchy."