Companies that make anything from guns, ammo, bombs, planes, uniforms, water bottles, helmets, boots, ships, food, shelter, computers, wires - literally anything you can think of that might supply the military, which is no BS everything you can think of, period, These companies ARE the military industry. They are simple companies, big or small, that try to sell to a customer. Their customer is the US government. They sell their products to the US government, with the goal of establishing a contract to continue to sell for years and years.

The conflict arises when men who make decisions to purchase these products (with a blank check from the US taxpayer) are the same men who have the power to make war, and also have friends who pay them - directly or indirectly - to buy the products. Now, these men have incentive to make war.

EL you're 5: Both sides have rocks and they're throwing them. I invent a slingshot. I get rich by selling slingshots to my side, because they buy crates of them, using a few dollars each of everyone on My Side, in the name of My Side Patriotism. My side now has a million slingshots, but now must invent new enemies to use all these slingshots on, to convince everyone on My Side that they didnt waste their money. Not only that, but I take the leaders of My Side out to dinners and buy them stuff, so they'll buy my next improved slingshot when it comes out. Now the leaders of My Side are really anxious to create conflict with the other side. ... or any other side.