DY, we have an obligation to conquer EY (Rambam Sefer HaMitzvot, mitzvot that Rambam “forgot”). Pikuach nefesh does not push off an obligatory war. That is obvious. In any case, they do not need any actions of ours to be incited. What did the Jews of Chevron do in 5689? Nothing but sit and learn. For that matter, what did the Jews of Europe do (according to Rav Teichtal, it was they did not do – make aliya en masse)?
Mobico, if you are referring to the Three Oaths, that is a halachic non-starter.
1. They are not paskened in any of the codes.
2. Rav Chaim Vital says in his introduction to Sefer Etz Chaim that they were only for 1,000 years.
3. Rav Meir Simcha says that the San Remo Conference revoked them.
4. Rav Soloveichik says in “Kol Dodi Dofek” that Hashem has called as evidenced in the miracles of Israel’s creation and this is a revocation.
5. They broke their oath not to persecute us “too much” on several occasions- the Crusades, the Chmielnitzki massacres, the pogroms and, of course, the Holocaust – so the whole deal is off (see Sota 10a Rashi d”h huchal and Shulchan Aruch Yoreh Deah 236:6).