Let's forget about Terrorism for a second, which does not exist anyway. It doesn't live anywhere and we can't physically kill it. It's just an abstract noun. Do we want to fight Afghans?--invade Afghanistan. Do we want to fight Iraqis--invade Iraq. One must declare war against nations, not against abstract nouns or sub-groups within a nation. That's why we never win. Once upon a time, the US invaded countries only for commercial interests. Today, the military and the national security apparatus does things on its own accord to stay in control. But since generals don't understand the concept of fiscal responsibility and budgets, they will compel our politicians to drive our government into bankruptcy.
We already have troops within the US that we call federal police forces that are essentially equipped the same way as our military forces. We just don't call them soldiers. The FBI, DEA, CBP, ICE, TSA, ATF, US Marshals, Secret Service, USCG, and CIA are the bulk of them. The US has been a national security state for 65 years. It is a police state now as well.