If the Quartet says that it is reality, then it is reality. Israel may be able to write American policy toward Israel, but there is little they can do to change the policy agreed upon by all four Quartet members. This is another battle that Israel doesn't want to fight. What Israel will likely to in a situation like this is to cooperate, but just barely and with as much delay and side tracking as possible.
Two Turkish journalists jailed over Syria smuggling reports (AP)
from the article: EU: Abbas close to accepting direct Mideast peace talks