Is it permissible to deal with an occupier of Muslim lands like Israel, and does that entail the impermissibility of dealing with its allies like America and European Union countries, given that they are occupiers of Afghanistan?

It is permissible to engage in buying, selling, and leasing with disbelievers, unless the matter is forbidden. The Prophet, peace and blessings be upon him, and his Companions, dealt with them. This permissibility also extends to the disbeliever at war (Harbi). If a Harbi enters the Abode of Islam as an envoy or a merchant, he is granted safety, and it is not permissible to harm him. And if a Muslim enters the Abode of War as an envoy or a merchant, he is under their protection, and they are under his protection. It is not permissible to betray them regarding their wealth or to deal with them through usury. And if it is permissible to deal with a Harbi, then it is permissible to deal with those allied with him. It is permissible for Muslims to boycott some disbelievers if they see a benefit in doing so.