*Updated 2020

The debate over when the US should intervene militarily in foreign countries dates back more than a century, and the US will have to confront this question as long as it remains a world superpower. In 2016, President Trump was elected, in part, on his promise to avoid military engagements overseas. However, his foreign policy over the years has shown – with strikes against the Assad regime in Syria, tensions that gave way to talks over North Korea’s nuclear program, increased US troops in Afghanistan in 2017 (which may finally see a withdrawal and an end to a nearly two-decade-long war in that country), and military confrontation with Iran – that isolationism is not necessarily possible.

Here are three reasons for intervention abroad and three against, focusing on cases in which there is no direct and immediate threat to US security.

The US should not get involved in foreign countries

Intervention rarely benefits the US

The last large-scale US intervention came in 2003, when American forces overthrew the Saddam Hussein regime in Iraq and began an eight-year occupation. That war alone cost the US more than $2 trillion and the lives of nearly 4,500 American soldiers. Though it’s been estimated that since 2001, America’s post-9/11 wars and military action in the Middle East and Asia have totaled $6.4 trillion, a number that will surely grow.

When it comes to American wars of choice, the Iraq experience is no outlier. Though the US is capable of defeating any enemy, the cost of doing so in both human lives and money is usually far greater than anticipated. Wars like Iraq and Vietnam, the latter of which saw nearly 60,000 American soldiers killed, are a case in point. But even smaller scale interventions, like President Clinton’s 1993 mission in Somalia or the overthrow of Libyan dictator Moammar Gaddafi in 2011, have had unintended consequences. (And let’s not discount that Americans paid higher gas prices after airstrikes killed Iran’s top military commander at the beginning of 2020.)

When core US interests, such as the security of its citizens, are at stake, Americans may have no choice but to bear these consequences. But more often, the consequences of military action outweigh the benefits.

And it rarely benefits the country of the intervention

From the invasion of Hawaii in 1893 to the bombing of Syria in 2017, it is the norm for US intervention to be justified on humanitarian grounds. In some cases, this may truly be the motive. Case in point, punishing the Assad regime for its use of chemical weapons against civilians. But rarely does military action improve the lives of ordinary citizens.

The US mission in Libya was aimed at stopping a civilian massacre by the government. It may have done just that, but Gaddafi’s death in 2011 led to civil war and chaos in the country, with ISIS gaining a foothold. Post-occupation Iraq looks no better, while Afghanistan remains unstable 19 years after the US invasion. And if we go back a generation, wars in Southeast Asia devastated the region while bringing little benefit to its people.

America should not be the world’s police

Beyond weighing the pros and cons of each intervention, supporters of US action overseas must answer a broader question: When does a country have the right to intervene in another country?

The UN Charter, signed after World War II, requires authorization from the UN Security Council to use force. Respecting an internationalized body’s authority to decide on such issues is preferable to allowing any one country to act alone. Also, American foreign adventures make it more difficult for the US to criticize aggression by other powers, such as Russia’s invasions of Crimea and Georgia over the past decade or Iran’s involvement in Syria and Lebanon. With the US withdrawing from the UN Human Rights Council, not to mention its intention to withdraw from the Paris Agreement, as well as cutting its funding to NATO and the World Health Organization, it seems that the US, is demoting itself from the role of being the world’s police.

America can be a force for good

Inaction also has consequences

Too often, US military action is judged against a perfect alternative. Yet, while intervention has its drawbacks and complications, failing to act often carries an even steeper price.

Avoiding confrontation sometimes puts American citizens at risk. President Clinton had the chance to kill Osama bin Laden several times but did not pull the trigger. A strike that killed al-Qaeda’s leader but resulted in civilian casualties may have earned criticism – indeed, it may have ended up in the other half of this column – but it could have prevented the 3,000 lives lost on 9/11 and avoided a wider war in Afghanistan.

Then, there are the humanitarian costs of inaction. Clinton called his failure to stop the genocide in Rwanda, where 800,000 people were killed in just two months, one of his biggest regrets. And what do Presidents Obama and Trump think about Syria, where over half a million people have been killed since 2011.

Intervention sometimes helps

Opponents of US intervention often point to cases in which American forces arguably made the situation worse. But Americans have also fought to prevent genocides, dethrone brutal dictators and uphold global norms.

In 1991, Operation Desert Storm prevented Saddam’s permanent annexation of Kuwait, an act that otherwise would have encouraged any dictator to snatch up smaller neighbors without fear of consequence. In 1995, NATO’s campaign in Bosnia following massacres in Srebrenica and Markale brought Bosnian Serbs to the negotiating table, leading to the Dayton Peace Accord. US forces left a decade later, without a single American killed by enemy fire. Even in Afghanistan, American intervention freed the population from the repressive rule of the Taliban.

The alternative is worse

It may be nice to imagine a world in which differences between nations are resolved only through diplomacy. But were the US to take a step down from the international stage, it would not be the UN that would fill the void. Russia and China, both countries less committed to humanitarian ideals than the US, would step in – as Russia is said to be doing in the Middle East. We need only to look back at the last time another superpower – the Soviet Union – challenged the US for global supremacy; only because of US protection was Western Europe able to thrive without falling to the grasp of Soviet tentacles. Meanwhile, regional hegemons like Iran would be free to impose their will on smaller nations without the credible threat of sanctions and force from the US.

The Bottom Line: US intervention overseas is never ideal and rarely uncomplicated, but the alternatives could potentially be worse. If you had the job and were facing the current threats from North Korea, Syria and Iran, what would you do?