It is becoming obvious to more and more people that the real reasons for so many wars is not nation building, not bringing democracy, not even overthrowing tyrants. The real reason is empire.
Find a country with resources you covet then invent a reason palatable to the unthinking masses and promote the just reason for war.
To the victor belong the spoils. Be it oil, or other mineral deposits, the drug business or just to get access to the land for more military bases or pipelines war is the answer. Justify the war in the eyes of the public and you can do what you want.
There is always money for war. At present over 51% of money raised by taxes by the US Government corporation goes towards war, munitions, paying the troops to do the dirty-work and developing more interesting ways to destroy and kill.