I doubt Obama's shunning of the Knesset has anything to do with Lieberman. I suggest that it is Netanyahu's criticism of Obama in the joint session of Congress, at the behest of Eric Cantor, that played decisive role. Obama has, and so he should, long memory. Netanyahu's speech was a n insult to the president, but then Netanyahu was cock-sure Obama was a one-term president. Everything has consequences. particularly bad judgements.
Western-backed Syrian rebels say kill foreign Islamic State (Reuters)
from the article: The diplomatic failure in Obama's visit