Maybe Israel got green light from the Quartet to build more settlements? It's only sensible to NOT negotiate as long as settlements project is ongoing. Is freezing settlements an unreasonable "condition"? You could think it this way: Israelis do have also a condition for talks, they must be allowed to continue settlements.
U.S., allies conduct 1 air strike in Syria and 11 in Iraq against ISIS militants (Reuters)
from the article: Israel accepts Quartet peace plan, urges Palestinians to follow suit