But the troops still have to acquire the special combat skills needed for urban warfare. This takes about a month of specialized training. And then the infantry battalions so trained have to go through a day or two of refresher training every month to keep those skills. Civilians tend to forget that successful infantry fighting is very much like a team sport. The team members have to train together to learn the moves that make the team effective, and than constantly practice those skills lest they lose them.
In the United States, the army and marines have been working on better ways to fight in urban areas for over a decade. While special training areas have been built, they are not large enough to train large (company size, over a hundred troops) units. Moreover, these smaller training areas can have a lot of their layout memorized by troops who have gone through them several times. This takes away the element of the unknown, which is such a major factor in street fighting. The army is building virtual reality battlefields to take care of this problem. Both the army and marines are working on new ways to use smart bombs and new equipment (like mini-drones, combat robots, sensors and better communications systems) for urban warfare.