A few weeks ago, the Atlantic Monthly Press released Mark Bowden’s excellent book, Hue 1968, A Turning Point of the American War in Vietnam. As he did previously in Black Hawk Down, Bowden brings the reader down the deadly streets of a savage urban battle, meticulously describing the action from the points of view the participants. Currently, the roughly yearlong battle for the Iraqi city of Mosul is drawing to a close. Although a half century separates these two classic battles, the similarities in urban combat far outweigh differences. Why is this so and what does it portend for the future?   

After 10,000 North Vietnamese soldiers slipped into the poorly guarded city of Hue in February of 1968, it took a month of intense fighting, principally by American Marines, to root them out. One reason was gross negligence by the high command in estimating the enemy’s strength. A deeper reason was the physical reality of urban density, trapped civilians, stout houses, and massive stonewalls. There was no avoiding house-to-house fighting to force back a determined enemy. In terms of total fatalities among friendly and enemy troops and civilians, the result was, to quote Bowden, “well over ten thousand, making it by far the bloodiest [battle] of the Vietnam War.”

Similar ferocity marked the Marine assaults against the Iraqi city of Fallujah in 2004. Eighteen thousand of the city’s 39,000 buildings were damaged or destroyed. More than 120 Americans and thousands of Iraqi civilians and insurgents died. Had it not been for modern medical techniques, about as many Americans would have been killed in Fallujah as in Hue. And over a decade later, it has taken 100,000 Iraqi forces (to include the Kurdish peshmerga soldiery) a year to kill or drive out the estimated 5,000 terrorists called ISIS from Mosul. Undoubtedly the toll, if ever accurately assessed, will be much higher than in Hue of 1968.

Urban warfare remains characterized by slow, massive destruction. Yet 50 years ago, there were no computers, no internet, no GPS, no UAVs, no digital communications, no night-vision devices, and no precision strikes. Two facts account for the lack of change in tactics. First, cities are constructed of steel and concrete, with streets providing the open spaces, which are usually linear. Any fighter in the open is quickly cut down. No technology can accurately detect and count humans inside buildings and tunnels. So the attacker must advance by blasting through the sides of buildings and slowly, slowly search every room. Second, tens to hundreds of thousands of civilians can be trapped in the cities. The terrorists in Mosul have prevented the civilians from leaving in order to use them as shields.

Most remarkable about the current city battle is that it is happening at all. In 2014, the Iraqi Army (IA) fell apart, surrendering Mosul to ISIS. Now they are on the verge of taking it back. The American advisory effort, to include consistent air and artillery support, was probably the key ingredient in the resurrection of the IA.

On the terrorist side, the only “new” weapon is the re-emergence on a massive scale of the type of kamikaze attacks used during the 1945 invasion of Okinawa. While no systematic data are available, the terrorists are employing suicide murderers on a scale and at a rate of historic proportions. In Mosul, advances by a friendly unit have included bulldozers to throw up defensive barriers, and every group of escaping civilians has to be carefully isolated and searched.

On the coalition side, the major change in urban warfare has been operational. In both Hue and Mosul, the attackers left an escape route for the defenders, rather than fight a trapped and desperate force. Next up looms Raqqa, the Syrian redoubt of ISIS, where Secretary of Defense James Mattis has ordered encirclement for a “battle of annihilation,” rather than allowing the terrorists to pull out and fight elsewhere. Whether the attacking Kurdish and Sunni forces will actually pursue that course will be seen over the course of the next several months.

Beginning with Desert Storm in Kuwait in 1991, American air superiority to detect and destroy enemy vehicles and troops has given the U.S. an enormous edge in conventional force vs. force warfare in open terrain. Looking forward, however, more fighting will occur in cities simply because the global trend is toward urban immigration. Urban battle will remain a slugfest, with the basic ingredient remaining heavy doses of high explosives. No technology is emerging to replace that.