Why doesn’t Israel sacrifice bulls, goats, lambs anymore like they did long ago?
Technically, the mosque on the Temple Mount in Jerusalem is “in the way”, but obviously it’s more complicated than that. Big changes, as well as all national and universal mitzvot like building the Third Temple, must be done slowly and surely, and with the initiative and support of the entire nation of Israel, and if possible, all of mankind, “for My House will be a House of prayer for all the Nations” (Isaiah 56, 7). We’re undoubtedly not there yet. Additionally, Rav A. I. Kook, the first Chief Rabbi of Israel, deals extensively with the possibility that there may not be animal sacrifices in the future Temple, maybe just vegetarian ones (“m’nachot” from oil, wheat, wine, spices, etc., Kvatzim miKtav Yad Kodsho II, pp. 15-17). In addition, the fact that the God who runs history has apparently decided that the time isn’t right yet, because we can just imagine what kind of international crisis with the Muslims would be caused by rebuilding the Temple (this is also an halachic factor). On the other hand, we must do whatever can be done, even if it’s theoretical at this stage, for example, studying the topic, preparing the necessary utensils and garments, and most importantly, educating towards a desire and strengthening the motivation to want to revive the sacrificial services, and all mitzvot which we aren’t presently observing. With Love of Israel, Rav Ari Shvat