Israel passed  a message to Syrian President Bashar al-Assad through an intermediary that it would take military action in Syria if Iran is allowed to establish a permanent military presence in Syria.
Ehud Yaari, Middle East analyst for Hadashot News (formerly Channel 2), reported the story and revealed Iranian plans to build “a naval base, possibly for submarines, an air base and arms factories for precision weapons” and that if Assad “invites Iranian forces to establish themselves in Syria via an agreement of any kind,” Israel will change its current policy towards Syria.
Israel has not intervened in the Syrian conflict but has taken action to prevent the transfer of sophisticated weapons to Hezbollah and to prevent military infrastructure being established on its border.
On November 10, BBC News reported  that Iran is establishing a permanent military base inside Syria. The Iranian military is said to have established a compound at a site used by the Syrian army outside El-Kiswah, eight miles south of Damascus (and 31 miles from the Golan Heights). Israel vowed to prevent this, with Netanyahu telling the BBC News, “You know, the more we’re prepared to stop it, the less likely we’ll have to resort to much greater things. There is a principle I very much adhere to, which is to nip bad things in the bud.”
Israel currently operates several field hospitals near the Syrian border as part of “Operation Good Neighbor.” According to the Israel Defense Forces, they have provided  aid to 200,000 Syrian citizens living in the Hauran region of southwestern Syria.
(via BICOM )