Tanks and infantry are supposed to operate together, and complement each other. But from the time when tanks were first invented (in 1915), getting the two groups to train together was always difficult. Part of the problem is that infantry and armor are two different branches, There are armor battalions and infantry battalions. Attempts to form joint infantry/armor units has never worked. For a long time, the lack of cooperation mainly had to do with the tank people concentrating on developing tactics for tanks alone. Infantry always saw tanks as a useful weapon to work with them. This was what tanks were invented for in the first place. But the tank folks saw themselves as the descendents of the horse cavalry. The cavalry never operated mixed in with infantry, but mainly as purely cavalry units. Despite tanks being invented to work closely, the tank crews were never enthusiastic about this. But in wartime, they discovered that a tank with friendly infantry nearby survived longer. But in peacetime, there was no enemy infantry to remind the tank crews how vulnerable they are. This has become more of a problem as modern tanks got larger and more dangerous for infantry to be around. The most dangerous elements of modern tanks are the larger engines and bigger guns. Its common for tanks to have 1500 horsepower gas turbine engines. These beasts throw a lot of very hot air out the back of the tank. This makes it impossible for infantry to move along right behind the tank. Its dangerous in front of these tanks as well. When the 120mm gun is fired, three things happen. First theres the sound of the gun going off. Its extremely loud, loud enough to make a soldier temporarily deaf. Then theres the shock wave of the 120mm round leaving the barrel. This concussion can knock a man down and is generally an unpleasant experience. The third element is most dangerous. Anti-tank shells use a sabot, pieces of metal around the long, needle like penetrator, that fall away from the penetrator a few hundred meters away after the shell leaves the barrel. The sabot fragments can wound or kill anyone in the way. Another problem is smoke grenade launchers on most tanks. These grenades use red phosphorus, which can provide a burn anyone it hits, while the smoke will cause choking. So infantry tend to stay away from modern tanks because these vehicles are hot, loud and dangerous. But in combat, especially in forests and cities, tank crews will find nearby enemy infantry also hot, loud and dangerous.