Let's make sure to convince our enemies to sign an agreement that when they attack us, they will:1) Use only bus-sized or larger missiles
2) Give us the path & trajectory information 90 days in advance
3) Not take any defensive counter measures
4) Send only a single missile at a time, with no multiple warheads
Then it should work like a charm every time!
And as a commenter there mentioned:
5) Wait to attack us until the weather is clear.