why Israel won't give air defence system to Ukraine..

Pressure on Israel to send defensive weapons to Kyiv reached a tipping point after Russia's use of Iranian drones in the war. 

Israeli minister Nachman Shai

said iran's involvement in the war had left no "doubt on the position Israel should take". 

Ex-prime minister Netanyahu's promise to look into arming  Ukraine if elected again complicated matters for the ruling coalition further. 

As a result, Defence Minister Benny Gantz issued an unequivocal refusal to supplier air defence systems to Ukraine.

"I would like to emphasize that Israel will not transfer weapon system to Ukraine due to a variety of operational considerations"-Israeli Defence Minister said.

Gantz also said Israel could provide an early warning system to Ukraine, an offer Kyiv's envoy  dismissed as not relevant anymore.

The former head of the Jewish agency for Israel was even more critical, accusing Israel of being "afraid to irritate Putin".

Israeli newspaper Haaretz reports widespread support for Gantz's position in the country's defense establishment.

Russian former leader Dmitry Medvedev warned that Israel's reckless move to supply weapons to Kyiv will destroy all bilateral relations. 

Moscow could  use Israel's argument on defensive arms supplies to Ukraine to arm Tel-Aviv's arch rivals in the middle East. Israeli defense officials fear Russia could supply air  systems like the S-300 and the S-400 to Iran  and Syria. the Israeli air force also stands to lose its uncontested control over the regions airspace.

Israel has frequently carried out airstrikes inside Syria at alleged Iranian targets, with the tacit approval of Moscow. Moscow has also agreed to remove its s-300 system and drawn-down it forces from Syria, as per-New York Times. 

The reported move follows Israeli concerns over s-300 missiles taking aim at Israeli jets during air raids.

Israeli officials are also worried about air defense system supplied to Ukraine striking Russian planes. 

Putin blamed Israel for an alleged Syrian friendly strike on a Russian spy plane in 2018, which killed 15 Russian soldiers aboard. Tel-Aviv is also worried about the west open support for Ukraine's request for Israeli air defence systems as per Haaretz. US lawmakers, including the head of a powerful senate subcommittee on the  middle East, are becoming more critical of Israel. Republican Rep. Adam kinzinger said Israel was "out of excuses to sit on the sideline and pretend it can do anything".