The tragic acts of terrorism committed in Paris on Nov. 13 have led to renewed calls for a more aggressive campaign against ISIS. Such calls are understandable given the shock and horror that always follows such barbarism. But simple revenge risks repeating the strategic mistakes of the past decade.

As we learned from Iraq, Afghanistan and Libya, military victory isn’t easy. Securing the peace can be almost impossible. If we truly want to defeat ISIS, we must focus not on military victory but on what comes after ISIS. Without resolution of the diplomatic and political conflicts that have allowed ISIS to bloom, what replaces it could be just as bad — or worse.

The events in Paris, the deadliest terrorist attacks in the West since 2004’s Madrid train bombing, were horrifying. In a free society, we can reduce the likelihood of such attacks, but we can never achieve absolute safety. In light of such an attack, fear is unavoidable, and calls to respond with overwhelming force are inevitable.

Yet any new military action against ISIS — or even intensifying current efforts — risks repeating past mistakes. The fear-driven environment following the 9/11 attacks undoubtedly contributed to the U.S. invasion of Iraq, as policymakers paid too little attention to what would replace Saddam Hussein.

The result was an effective military campaign followed by a decade of instability, insurgency and bloodshed, which provided fertile ground for the growth of groups like ISIS.

Likewise, in a knee-jerk response to mass killings in Libya in 2011, NATO airstrikes helped to topple the Muammar Gaddafi regime. Yet a lack of effective planning led policymakers to overlook that the only shared interest of the many local groups and regional powers involved was Gaddafi’s removal. After his death, multisided flows of weapons and renewed violence undermined any hope for a stable Libya.

Such prior failures highlight that no matter how raw emotions may be after brutality like that of the Paris attacks, policymakers need to take the long view. Syria remains a muddled quagmire of differing rebel groups and regional acrimony, which military action alone cannot solve.

The downsides of extreme options like a large-scale invasion of Syria are obvious. Certainly, there is no doubt that the U.S. military could easily destroy ISIS or even the Bashar al-Assad regime. But there is nothing to fill the gap such actions would leave. As in Libya, regional powers and local militias barely accept the need to cooperate on ISIS; they will not suddenly cooperate in its absence.

But the current U.S. strategy is equally problematic. Increased bombing raids, more special operations forces or funneling arms to Syrian rebel groups may provide gains on the ground against ISIS. But when ISIS collapses, what comes next? The scenario is the same: anarchy and further bloodshed in Syria, from which future ISIS-like groups can spring.

If we are to avoid this, policymakers must first build the diplomatic and political bridges that lead to a stable post-conflict Syria. A clear and effective diplomatic accord to end the Syrian civil war is key, though it may involve substantial compromise on the part of the U.S., especially on the timing of Assad’s departure. Deals with dictators are seldom pleasant, but as many have noted, any peace in Syria is better than the current war.

The U.S. will need to work closely with regional allies and even adversaries to enforce and sustain this peace. A political settlement is meaningless if the ceasefire is not observed or if regional states continue to supply weapons to favored rebel groups as they did in Libya.

Emma Ashford is a visiting research fellow at the Cato Institute. Send comments to [email protected].