[rocqua]

Piecemeal deployment might work, if not discovered. But the discovery risk is rather large.

When an opponent discovers the deployment, either after-the-fact, or during deployment. They have many responses beyond immediately launching everything. The main problem is that this deployment corners them. Perhaps they try to attack the missile shield in space. Perhaps they run covert operations to disable the shield. Perhaps they take economic warfare counter-measures. I imagine plenty of former allies might side against whomever made such a huge uni-lateral move.

In any case, as we say in my native language, a cornered cat makes weird jumps. I don't think it makes sense to corner China or Russia in this field. MAD works well enough.