Syria has been a breeding ground for terrorists, we knew that before 9/11. We chose to invade Iraq. Hummm, Iraq has oil, Syria has ..... terrorists.
The war on terrorism is just like the 'war on drugs'. Just another way to gain political power for the Presidency.
To answer your question:
do the countries we are using drones in consider them to be acts of war against them?
America is the most powerful country in the world. Our military has no equal. We spend more than the next 10 free Nations on military. We've become the bully on the block. No other country would dare oppose us. The only exception is terrorists.