In addition to what Ven. Yuttadhammo and Nina mentioned:

On Thu, Dec 1, 2011 at 7:12 AM, Yuttadhammo <yuttadhammo@...> wrote:
> Fourth, weapons in general are considered "untouchable" by the commentary, touching which is subject to a dukkaá¹­a... can't find the canonical basis for it, but here's the passage in the commentary (to pÄ rÄ jika #2):



> --- In Pali@yahoogroups.com, Nina van Gorkom <vangorko@...> wrote:
>>
>> Dear Bryan and Sister Dipa,
>> thank you. The life of a bhikkhu and bhikkhuni is a life with non-
>> violence. Think of the Parable of the Saw: even if robbers would saw
>> off your limbs, you still should have mettaa. It is not in the spirit
>> of the teachings to carry weapons. Caravan would be the only
>> possibility I would think.
>> Nina.



I don't think that it would be wise to recommend something that could
have the Bhikkhuni expelled from the order:

Pārājika: Rules entailing expulsion from the Sangha (Defeat)

[.......]

3. Should any bhikkhu intentionally deprive a human being of life, or
search for an assassin for him, or praise the advantages of death, or
incite him to die (saying,): "My good man, what use is this evil,
miserable life to you? Death would be better for you than life," or
with such an idea in mind, such a purpose in mind, should in various
ways praise the advantages of death or incite him to die, he also is
defeated and no longer in affiliation.

[.......]


--
Hugo