If you are looking at the influence of intelligence upon decision making at the national strategic decision-making level, then I highly recommend giving a read of a book I've recommended on this board a couple of times: Knowing One's Enemies: Intelligence Assessment Before the Two World Wars

The book was published by Princeton University Press in '86 and consists of sixteen essays that describe in fair detail intelligence collection, analysis and decision making at the national level in countries about to go to war (Austria-Hungary, Germany, Russia, France, Great Britain and Italy before WWI and Great Britain, France, Germany, Italy, Russia, Japan, and the US before WWII).

And, although they don't go into as much detail on the strategic intelligence feed into national-level pre-conflict decision making, I also recommend Irresolute Princes: Kremlin Decision Making in Middle East Crises, 1967-1973, Chinese National Security Decisionmaking Under Stress, and Who's at the Helm? Lessons of Lebanon. There's more, but that's just an off-the-cuff recommendation before I go get my post-lunch coffee.....