It doesn't matter any more. The aliens already play Go.
This is a well-documented fact.
Emanuel Lasker, chess grandmaster and one of the early Western Go players, already observed this by saying: "If there are sentient beings on other planets, then they play Go".
And a bit earlier, Oskar Korschelt, probably the first person to bring the rules of Go to Europe, noted that "Go is not just the picture of a battle, as chess is, but that of an entire campaign, a campaign of the modern kind" ("Das Go hingegen ist nicht blos das Bild einer Schlacht, wie das Schach, sondern eines ganzen Feldzuges und zwar eines Feldzuges moderner Art").
We can conclude that when the aliens arrive to make war, we might win some battles due to our superior abilities at chess-style battle tactics, but we will lose the war (Japan and Korea might resist for a while, but we can't expect them to save the whole planet).
Luckily, the game of Go, unlike chess, is not about total annihilation.