Arms manufacturers influence on foreign policy

What kind of influence do arms manufacturers have on foreign policy, or on strategic decisions in the field even once a war is ongoing? Take operation arc light during the vietnam war for example, where over hundredthousand sorties were flown to basically bomb dirt most of the time.

The manufacturer of the 750 lbs and 1000 lbs bombs used in the over 120.000 sorties conducted during the war literally earned billions of dollars. Do you think arms manufacturers have a lot of weight when a decision must be made to go to war? Do you think they might even be able to pull some strings to have the war conducted in a way that is most profitable to them?

Those were rhetoric questions, right? Because... well... yeah.

Of course the arms manufacturers want more customers. Not neccessarily involved in a war, but a sale is a sale..