Would the oaths be permitted according to someone who believes that the Lubavitcher Rebbe is moshiach?
Have you read Rabbi Gil Student's book, "Can the Rebbe be Moshiach" with large
segments available at http://moshiachtalk.tripod.com/
This may seem a bit off the main topic of our usual discussions, but I
think that it is relevant to it. Here's why: All other arguments pro and
con about the oaths aside, it seems to me that if one conclusively believes
that Mashiach is here now, has been here and will return again, or some
combination thereof, and has already succeeded in fulfilling his criteria,
then the oaths are officially breakable. After all, according to the
supporters of the oaths, what but the presence of Mashiach permits the oaths
to be abrogated? Thus, if one holds that R. Shneerson was/is/will once
again be Mashiach, then Jewry has already had the right to abrogate the
oaths.
And just as one side point, according to one person who is of the belief
that R. Shneerson is Mashiach (so obviously an avid supporter and student of
R. Shneerson), he mentioned to me that R. Shneerson advocated paying the
Arabs to leave the Land of Israel, an act that would clearly not be in sync
with promoting the idea of giving the government of Israel to the gentiles.
But such a thing would only matter to a promoter of the oaths if one truely
was convinced that the Rebbe was/is/will be Mashiach. Thus, you must be
able to conclusively refute the Torah source arguments of those who hold he
is Mashiach if you are to maintain your position that the oaths are not in
fact batul. Which is another reason to read all of R. Student's book. Just
my thoughts.
On the other hand, the Rambam says that if moshiach is killed, he is not the one. Dr. Berger saw this as a definitive ruling against the Abarbanel's concept of a moshiach who dies and comes back. There are three possibilities as to why the Rambam held this way:
1) The Rambam did not pasken like the Gemara that moshiach could come from the dead at all;
2) He did pasken like it, but held like Rashi that it would have to be Daniel and nobody else;
3) He held that moshiach could die and be resurrected, but only if he did not begin to fulfill his messianic mission in his first life. The Rambam describes a scenario where the moshiach starts to do his job but then dies in the middle, like Bar Kochba. That is unacceptable because Hashem would not do that do us bring us moshiach and then take him away.
According to this last pshat, it could be there is no machlokes between the Abarbanel and the Rambam. Even the Abarbanel agrees that moshiach cannot be someone who started and then died.
You once mentioned to me that some Lubavitchers claim that the Rambam says "was killed" but not "died", meaning that if the messianic candidate died of a stroke he could still be resurrected as moshiach. Rabbi Student countered that the Rambam's words "he did not succeed to this degree" refer to death because this is the only way one can be sure he will not succeed. The problem with this is that why then did the Rambam have to mention the case of "was killed" at all? Is that not included in the words "did not succeed"? Rather it would seem to me that any failure, even without death (such as Shabsai Tzvi's conversion to Islam) is enough to disqualify him. The words "was killed" are lav davka since there is no logical difference between dying of a stroke or being killed.
Regarding the oaths, this whole issue is academic, because even if the Rebbe were alive and we were to assume that he is moshiach, it wouldn't allow us to violate the oaths until he has accomplished the first stage of his mission: making every Jew repent. Therefore, certainly now, even for someone who believes that the Rebbe will be resurrected and be moshiach, we are not permitted to violate the oaths.