In Kuwait, there is a training site where soldiers learn how to open doors. Since much of their work involves acting on tips from locals regarding buildings where militants may be hiding weapons caches, bomb factories, or themselves, the soldiers need to learn this. They use various methods to open doors. Sometimes a simple knock will do, but sometimes the information is so urgent that bursting through a door is best.
The training site features a long masonry wall with multiple doorways hung with doors of different materials, strengths and styles. The soldiers go from door to door opening them with either a crowbar, maybe a shotgun blast, or an explosive charge that blows the door off its hinges.
At the end of the row, the soldiers take a break while a local contractor and crew cleans up the mess. They jump down from their truck which is piled high with new doors, and make quick work of hanging and locking them for the next go around. They do this all day long, but hey, it's work.