Proxy and civil wars will continue to flourish, as will conflicts on the peripheries of power blocs. The danger of inadvertent escalation is high. The planet has already survived the Cuban missile crisis of 1962, the Soviet false alarm of 1983, and the Norwegian Black Brant nuclear-rocket scare of 1995. Eventually our luck might run out, and when it does, cities will likely be ground zero. The world’s city-dwelling population exploded from 746 million in 1950 to 4.2 billion in 2018, according to the United Nations (which expects that total to increase by another 2.5 billion by 2050). To dominate a nation has come to mean dominating its population centers.

There are reasons that coming wars will be more, not less, deadly. As weapons systems become increasingly accurate through satellite positioning, surgical strikes on military targets will seem more viable. But the blood-soaked history of “smart bombs” show that they have only been as smart as the intelligence used to deploy them. In 1991, laser-guided missiles entered the Al-Amiriyya bomb shelter in Iraq through a ventilation shaft, killing more than 400 civilians. In 2008, an air raid obliterated a bridal party at Haska Meyna. Such “aberrations” likely will increase in frequency.

Read: The video game that could shape the future of war

The “double tap” approach—one strike followed quickly by a second meant to target rescue and medical personnel—that has been favored by Islamist terrorists, CIA drones, and Syrian and Russian air strikes will continue to devastate civilian morale and the public’s ability to survive and recover. Absent repercussions, or just to test the geopolitical order, combatants might abandon even the appearance of avoiding civilian targets. That’s already happened in the Russian bombardment of civilian parts of Syrian cities.

Even an “ethical” attack, on infrastructure rather than civilians, will result in misery. Destroyed airports, downed bridges, disabled power stations, and disrupted communication networks will tear daily life asunder. The psychological impact upon children—living in basements; subject to the sounds and tremors of bombardments; isolated from social systems, education, adequate sanitation; facing food and medical shortages—is inestimable. Danger in the form of cluster bombs (which are still killing and maiming people in Southeast Asia decades after their deployment) and chemical weapons litters the wreckage that children play in.

The threat of attack has already changed the design of cities. Some had underground metros where people could take refuge; in Uzbekistan, Tashkent’s even boasted atomic blast doors. Beijing has an entire underground city called Dixia Cheng, built in case the Sino-Soviet split went nuclear, capable of sheltering millions of people. During World War II, Switzerland built enough bunkers for its entire population to disappear into, along with infrastructure that was rigged to explode upon invasion.