[Suicide Junkie]

Given 12 projects of Counter Intel 3 (500,000 points), when they're filled up, that's 6 Mil points.

You don't have to be actively adding to a CI project, it just has to have points stored in it.
If a CI project is completed (overflowed), that is a bad thing, and you lose your stored points.
If you don't overflow the CI project, the points will remain in place until enemy ops hit.
Each blocked op uses up some of your storage, and when your defense is empty, the enemy's projects will start to succeed.
Enemy attacks cannot slip through the defense unless the defense supply is either; less that the offense cost, or maybe zero.