"An irreconcilable attitude against bourgeois militarism does not signify at all that the proletariat in all cases enters into a struggle against its own “national” army. At least the workers would not interfere with soldiers who are extinguishing a fire or rescuing drowning people during a flood."
In the instances Trotsky gives ("extinguishing a fire" or "rescuing drowning people during a flood"), the imperialist soldiers would still be doing those things for "imperialist reasons" (to save the building for continued use by capitalism, no doubt). Would you say "no imperialist intervention! Troops out now! Turn off your hoses!" I imagine you probably would. I seem to recall you being in favour of the slogan "troops out now" as the sloganistic summary of what socialists should say about US "intervention" in Haiti after the earthquake.
And what about this bit -
"In ninety cases out of a hundred the workers actually place a minus sign where the bourgeoisie places a plus sign. In ten cases however they are forced to fix the same sign as the bourgeoisie but with their own seal, in which is expressed their mistrust of the bourgeoisie."