What is the ruling on loving weapons and military equipment manufactured by non-Muslims, not for the sake of their makers, but for their qualities such as speed and strength, knowing that some of them may be used against Muslims?

Admiration for modern weapons and their power does not necessitate respect or love for their manufacturers. There is no issue with Muslims using these weapons or with them being used against Muslims. The real issue for the questioner is obsessive doubt (waswasah), and we advise him to disregard it and not to overthink these matters.