"al tisgareh b'goy koton" ... is only when there is no psak din to the contrary...in the present case THERE IS A CLEAR RULING "TO GO OUT AGAINST THEM WITH WEAPONS"
...We must take an appropriately firm stand and not be flustered by a goy — because this is an issue which concerns saving the lives of many Jews.
This is the ruling of the Shulchan Aruch...which was accepted in all Jewish communities for all generations, until the coming of our righteous Moshiach.
And the psak din is that we need to have weapons, and this is an issue connected with avodas Hashem, just as it is necessary to learn Torah and perform mitzvos, all the more so when it concerns saving lives!
Indeed we are in golus, and there is the issue of "do not incite a small goy" [See Pesachim 113a] all the more so a "big goy," and there is the issue of "do not go up as a wall" (Kesubos 111a) — but this is specifically only when there is no clear psak din in Shulchan Aruch to the contrary, and in this case there is a clear psak din in Shulchan Aruch that "you go out against them with weapons."
And when one will ask a question if you are allowed to take weapons on Shabbos to save a Jew — so if he will be answered that "this day is holy to our L-ord" (its Shabbos kodesh) and therefore he must sit and learn Torah all day and he is forbidden to take up arms and save the Jew
[and he (further) argues that its written in hilchos Talmud Torah that every Jew is obligated to sit and learn Torah, even an old person and also a person who is in pain, all the more so on the day of Shabbos, and even more so in a time of literal danger, which is when one certainly must connect to Torah; as the well known analogy from Rebbi Akiva about the "fish in the sea" (Avoda Zara 3b)] —
he must know that he is doing the opposite of a clear psak din in Shulchan Aruch [Laws of Shabbos #329]: "goyim who besieged Jewish cities" so if it's a "community close to the border", even if they don't want to come only on matters of "straw and stubble," and even if they are only planning to come - "we go out against them with weapons and we violate over them the Shabbos".
When there is a decree against Torah-study - one particularly must study Torah (as was mentioned above the saying of R. Akiva); however when the "decree" is on "issues of straw and stubble" — then Torah says that even when we are outside Eretz Yisroel, and in golus we must take up arms (and know how to use them) and to go out from his location etc., because it's a matter which is dealing with saving lives.
27. Being that there are those who hold that its forbidden to speak firmly to a goy, so that the goy should not be angered — so Hashem demonstrated in the three wars, in all three it was seen what is the result of the policy when one feels inferior to the goy, and they don't want to comply with what is written in Shulchan Aruch.
Military officers said that if a certain territory will be returned it will cost lives, Hashem should save us. Came the politicians and argued from a "political perspective" that it is prohibitive to stand up to the goy — and what followed was that this cost tens and hundreds of lives, Hashem should save us!
(24 Teves 5738 –Likkutei Sichos v. 21 p.292)
