How strong the iranian army is?
That depends on which army you are talking about. Like so many totalitarian or fundamentalist states Iran actually has 2 army’s. The regular army and the Pasdaran who are religious zealots loyal to the regime whose primary job is to protect the government from the regular army. The Iranian armed forces are capable of protecting their own territory and they have a huge number of men under arms but they are not especially well equipped. British and American left-overs from the 1970’s and second-rate Chinese imports combined with local copies of 1970’s vintage equipment constitute the bulk of Iran’s heavy firepower. Not a first rate army by any means but I wouldn’t want to be the guy ordering an invasion of Iran either.