Syria's Assad inspecting the "Terminator" in Russia's Syrian air base last week
In just about every war since WWII soldiers have found fast-firing anti-aircraft guns to be extremely effective against...infantry.
In WWII the Americans nicknamed their M45 Quadmount — four 12.7mm machine guns designed for air defense — "meat chopper" and "Krautmower" for its utility in fighting enemy foot soldiers.
In Afghanistan and Chechnya one of the most beloved weapons of the Soviets/Russians was the Shilka. Not bad for an anti-aircraft weapon in a war where the opposing side didn't have an air force.
Designed as an air defense weapon (it even came with its own radar dish) the Shilka was very lightly armored for Afghanistan, but its four 23mm autocannons offered more useful firepower than either the potent, but slow, tank guns, or the single autocannon of the BMP-2 infantry carrier. Also it was the only Soviet weapon whose guns had sufficient elevation to easily fire on targets in the hills from valley floors.
Comment: The Russians obviously must be stopped. It's an obvious Commie trick. Just ask Assistant Secretary of Defense General Buck Turgidson!