Is covert military action constitutional?

What in the constitution gives the US government the right to take actions in other parts of the world that have nothing to do with defending ourselves--actions that cause others to hate me, and to retaliate against me when I have done nothing wrong? I didn't vote to have the US give military aid to Saudi Arabia, which oppresses its people. I really think something is wrong here--I didn't elect anybody who said they'd interfere in other countries business--is this really a democracy? I am not being represented by the US military.