By signing the NPT Syria has made a commitment not to produce Nukes and to allow international inspectors unfettered access to its nuclear sites. Syria has broken the "non proliferation" part of the treaty by embarking on this covert program, and has refused to cooperate with the IAEA. Case and point. Nothing to deal with Israel as Israel didn't sign the voluntary NPT treaty.
Joint Arab List's Odeh: I won't set red lines on resistance to occupation (Haaretz)
from the article: IAEA: Bombed Syrian plant linked to three more suspected nuclear sites