A crusade was called to protect Catholicism as a form of self-defense when Catholicism was attacked with physical violence, as when Islam forcefully took over the Holy Land, or when the Moors conquered Spain in 711. However, I do not see a pope calling for a crusade today. It is up to us to defend Catholicism the best we can by engaging in the cultural war (not a physical one). The new crusade could be the new evangelization.
crusade?

Yes, but what should the response be if, hypothetically, the Holy Land is taken and the faithful are barred from pilgrimages?

Prayer and fasting. The days may come when we may have to take up arms to defend home and hearth, or other Christians, but even if such a crusade was just—as it might be in the case of many Nigerian Catholics in need of help—the forces of evil arrayed against the Church (from within and without) are of such a quality and concentration that we must recognize them as proper to the Lord of the World in this very late hour. Which means, then, that our recourse is to strengthen what remains, continue to build up the Kingdom while we yet have breath, and wait on God. He has never failed to manifest his power and glory in the accomplishment of His will. Read the signs of the times but do not be ruled by them. Remember to Whom you belong and Where you are going.

Yeah, we have teachings on "just war" so that would limit a multitude of martial actions the Church could theoretically endorse or call for.

I don't believe it is the Catholic Church's duty to protect the nation of Israel, so I doubt a crusade would be called even if it were taken over by Palestinians. The Palestinians would be unlikely to prevent pilgrimages etc. as there has always been a Christian presence in Gaza and the West Bank that have lived there without much persecution.

I don't believe it is the Catholic Church's duty to protect the nation of Israel, so I doubt a crusade would be called even if it were taken over by Palestinians. The Palestinians would be unlikely to prevent pilgrimages etc. as there has always been a Christian presence in Gaza and the West Bank that have lived there without much persecution.
has there? I honestly fine that quite surprising considinerg how the rest of the muslim countries treat us.
say if, hypothetically, isreal somehow got conquered by say, palestine. would the Pope need to call for a crusade to retake the Holy land? if so, how would we do it? im not sure if modern nations, mostly controlled by atheistic groups (I think), would care about this at all. especially with how Europe has been starting to treat jewish and christiain culture, and have started to lean more woke..