U.S. presidents often leave the White House expressing “strategic regret” over perceived foreign policy failures.

Lyndon Johnson was haunted by the Vietnam War. Bill Clinton regretted the failed intervention in Somalia and how the “Black Hawk Down” incident contributed to his administration’s inaction over the Rwandan genocide. Barack Obama said the Libyan intervention was “the worst mistake” of his presidency. And after a tragic bombing killed 241 U.S. service personnel in 1983 at a Marine Corps barracks in Beirut, President Ronald Reagan called his decision to send troops to Lebanon “my greatest regret and my greatest sorrow.”

As the U.S. heads into a presidential election that will, in all likelihood, end the future White House ambitions of one of its two latest inhabitants – Joe Biden and Donald Trump – it is fair to ask whether either or both will end up similarly experiencing “strategic regret.”

As an expert on U.S. foreign policy and grand strategy, I believe that if history is any guide, a possible answer can be found in both men’s decisions to keep U.S. troops in Syria and Iraq.

With troops in both countries – about 900 in Syria and 2,500 in Iraq – facing missile attacks from Iranian-backed proxies of late, the U.S. could be edging toward another incident like the 1983 terrorist attack in Beirut, a point made all the more obvious by the recent deaths of three U.S. soldiers in Jordan along the Syrian border.

Another Beirut?

The Middle East has entered a volatile period. The threat to U.S. personnel in the region takes the form of both the Islamic State group, which is intent on hitting Western targets, and the increased risk from a network of Iran-linked militants seeking to avenge what they see as U.S. complicity in Israel’s siege of Gaza.

If any mass-casualty attack on U.S. forces were to occur, the occupant of the White House would face two conditions that have left departing presidents experiencing strategic regret: the loss of American lives on their watch and the prospect of being drawn into a widening war.

By historical standards, conditions could be ripe for strategic regret in the Middle East. Today’s situation in Iraq and Syria is eerily similar in many ways to the circumstances Reagan faced in Beirut, but potentially far more dangerous.

Like Lebanon then, U.S. troops are in Iraq and Syria for secondary, as opposed to primary, security objectives.

The troops in Lebanon in the early 1980s were peacekeepers. In Iraq and Syria they support a cleanup mission against an Islamic State group whose threat to U.S. national security ended with the collapse of the caliphate in 2019. According to a recent Pentagon report, that threat remains exceedingly weak today for the United States.

As in Lebanon, U.S. troops today are also highly exposed given their small numbers, hostile surroundings and dependence on Iraq, Turkey and Kurdish forces for supply lines. That makes them easy targets for attack.

While Reagan was unaware of the high exposure of U.S. Marines in 1983, the danger U.S. troops face today in Iraq and Syria is abundantly clear. U.S. forces have faced more than 160 missile attacks from Iranian-backed proxies since mid-October 2023.

The Jordan attack aside, U.S. service members have already suffered significant injuries from missiles, including dozens of traumatic brain injuries. With Iran saying in April that the U.S. “must answer” for Israel’s killing of three generals in Iran’s Quds Force this week in Syria, prospects of more deadly attacks against U.S. soldiers in Iraq and Syria appear to be rising.

Fueling hubris

Some might consider this concern about “another Beirut” overblown. After all, proxy attacks on U.S. forces in Iraq and Syria have dropped since the attack in Jordan in late January, giving the impression that deterrence is now working after big U.S. retaliatory strikes in February.

Here again, though, history tells a cautionary tale. The 1983 Marine Corps barracks bombing was preceded a few months earlier by a smaller, yet still deadly, bombing at the U.S. embassy in Beirut. In the lull that followed the embassy attack, Reagan officials didn’t pursue a strategically smart rethink of U.S. policy or consider troop reductions.

Instead, fueled in part by a determination to make the mission work, they doubled down and adopted a more aggressive role in Lebanon’s civil war.

It was a fateful decision. In short, lulls in violence like today in Iraq and Syria can fuel hubris and provide a dangerous sense of false security and a determination to stay the course.

As Lebanon – as well as Somalia under Clinton and Vietnam under Johnson – shows, that is a prime condition for strategic regret.

If regret does come over Iraq and Syria, there are reasons to believe that it could even be more profound for the current occupant of the White House than it was for Reagan in 1983. After the Beirut bombing, Reagan used the distraction of the Grenada invasion to quietly withdraw U.S. troops from Lebanon rather than escalate militarily and risk additional U.S. bloodshed.

Biden or Trump, should he replace the current Oval Office occupant come November, may not have the luxury of a Grenada-like distraction.

Rather, the intensely partisan politics in Washington, in which a president may seek to avoid being perceived as weak and criticized for doing too little, will settle in. Critics of Biden have already made charges like this over the attack in Jordan – that will only grow with another mass casualty event.

As research shows, “see, I told you so” is a powerful rhetorical tool in circumstances like this.

The ghosts of history

In response, Biden or Trump – like their predecessors – might feel the pressure to “go big” militarily. But anything too large risks inviting the kind of response that could lead to lasting and devastating outcomes.

Imagine, for example, a scenario in which a U.S. president is provoked into striking Iran following repeated attacks by Tehran’s proxies on U.S. troops. Iran, in such a scenario, will have little choice but to respond in kind.

The result would be an expansion of – and further U.S. involvement in – the Middle East conflict. And that is something that Americans generally don’t want.

The majority of progressives, young voters and Black Americans oppose war. MAGA Republicans do too.

Furthermore, the inevitable economic pain of war would likely see support evaporate at home and compromise America’s ability to dedicate resources and efforts elsewhere, notably in Asia and Europe.

None of this is inevitable; presidencies don’t have to end in strategic regret. And like their predecessors, Biden or Trump would have options. Presidents Johnson, Reagan, Clinton and Obama chose the wrong options and regretted it. Their experiences and the ghosts of history serve as a warning when it comes to U.S. forces in Syria and Iraq now. Perhaps that will lead to fewer regrets.

Charles Walldorf received funding from Charles Koch Foundation. Charles Walldorf is a Visiting Fellow, Defense Priorities