Let's say the world is threatened by eldritch monsters or nations at war. Instead of investing in tanks, aircraft and such, the government decides to invest in bioweapons that are basically monsters.
The monsters that I'm describing are usually human size, sometimes bigger or smaller. They all have different appearances and serve different purposes in combat.
But what would be a rationale or justification of a government making these living creatures for combat that accounts for what happens to them when the fighting is done and the risk of them on their creators?