I seem to recall the Persians getting kicked out of Greece not once but twice.
Yes, the Persians won at Thermopylae, which was the second major Persian invasion; wherein Xerxes brought over his 2.7 million men. But that was a battle, not the war.
The simultaneous naval battle at Artemisium was a stalemate. Xerxes went on to sack the deserted city of Athens; the inhabitants of which had fled to Salamis. The ensuing naval battle at Salamis was a shattering defeat for the Persians; Xerxes began retreating. What was left of the Persian army was finally defeated in detail at Plataea.
Sounds like a Persian loss to me. What war did the Persians actually win against the Greeks, again?
Why align yourself with people who hated monotheism and worshiped multiple Gods, were homosexuals, rapists, murderers, who hated democracy, freedom, human rights and treated women like dirt?
If you do you are a Spartan.