People are considered disposable too, if the mission value is crucial enough to save the lives of more people - enough so that there is a term for it 'expendable'. When your unit is declared expendable the mission objective is deemed more valuable than the lives in your unit, a rare thing that is supposed to happen only when the unit giving up their lives can save many more. I learned about expendable units from my dad, a radio operator at the tail end of the Korean War. Airborne leadership expected the North Koreans to attack during the treaty talks. My dad's unit was placed where they'd likely attack and told to give early warning and attempt to slow them down, at all costs - that they were declared expendable.

Thankfully they didn't attack or I wouldn't likely be here. There's a good story linked below about an expendable unit in Burma named Merrill's Maruaders [1].

Other animals have been used in more questionable ways too, such as the Navy Marine Mammal Program's use of dolphins to find and mark mines [2]

[1] https://www.army.mil/article/173880/expendable_wwii_merrills...

[2] https://en.wikipedia.org/wiki/United_States_Navy_Marine_Mamm...