Is he who does not declare an infidel to be an infidel himself considered an infidel? And how are the People of the Book and the polytheists declared infidels? Is it sufficient to believe in declaring an infidel everyone who commits an act that expels him from the religion, with the exception of the people of the Fatrah (those who lived in a period without a prophet) and the ignorant?

The meaning of disbelief in Taghut is that you disavow whatever is worshipped besides Allah, and that you bear witness to the disbelief and misguidance of anyone who worships it, and you detest them. Their disbelief must be believed in, and then they should be treated according to the rulings for a disbeliever. However, this is not easy for individual Muslims; rather, it is carried out by scholars and legitimate judges, while considering impediments to declaring someone a disbeliever, such as ignorance, coercion, and misinterpretation. The Prophet, peace be upon him, warned against accusing a believer of disbelief, considering it akin to killing him.