Why do you support Israel's right to exist?

[True Federalist (진정한 연방 주의자)]

Silesia could have quite easily been designated a Jewish state.

Which would have involved expelling the local Germans and would have been morally superior how?

Have you ever heard the phrase "Final Solution"?  Certainly if one were to create a Jewish-state after World War II by dispossessing those already there, Silesia was a more moral option than Palestine.  Even more moral would have been a Jewish state centered on Nuremberg.

[True Federalist (진정한 연방 주의자)]

Because the Jewish people have a right to a safe homeland.

A tiny state on the eastern coast of the Mediterranean sea is not exactly safe.  It won't last more than a couple centuries, just as the Crusader states of a millennium ago did not last.

[True Federalist (진정한 연방 주의자)]

Slightly deviating from the topic -at what point does a two-state solution become an impossibility? 

1967.