The accidental downing of a Russian plane with 15 soldiers on board has tested relations between Moscow and Israel, which fears President Vladimir Putin will seek to curtail its actions in Syria as a result.
Analysts say they believe Russia and Israel will eventually move past the incident without severely limiting Israel's freedom of action in Syria, where it has carried out hundreds of strikes against Iranian and Hezbollah targets.
But Russia, whose plane was shot down by Syrian air defences after an Israeli strike and strongly criticised Israel over it, has since announced it plans to send an advanced S-300 air defence system to the Syrian military.
It also says it will jam communications of planes that attack Syria from the Mediterranean.
Israeli Prime Minister Benjamin Netanyahu has so far sought to strike a balance between expressing sorrow over the Russian deaths, stressing his commitment to cooperation with Moscow and vowing to continue to act against Iran and Hezbollah in Syria.
"We will continue to act to prevent the Iranian military entrenchment in Syria, and continue the security coordination between the Israel Defence Forces and Russian army," Netanyahu said Tuesday.
- 'Very serious issue' -
But Netanyahu's government has little choice but to take into account Russia's anger over the incident and the potential risk to Israeli aircraft, analysts say.
In deciding to provide Syria with the S-300 system, Russia overrode years of Israeli opposition to supplying President Bashar al-Assad's regime with the technology.
Eran Lerman, former deputy director for foreign policy at Israel's National Security Council, called it a "very serious issue" that could amount to an "intolerable situation from an Israeli perspective".
But he added that it seems communication "channels remain open and operational".
"We don't work for the same purposes, but we have a common interest in preventing clashes," said Lerman, adding that there are "mutual understandings" that can eventually prevail.
Israel and Russia put a hotline in place in 2015 to avoid accidental clashes in Syria.
In recent years, Israel has carried out repeated strikes against Iranian targets in Syria as well as what it says are advanced arms deliveries to Hezbollah.
It has hit Syrian sites where those targets were located.
Iran and Lebanese Shiite group Hezbollah, two of Israel's main enemies, are backing Assad in his country's civil war alongside Russia.
Israel also remains technically at war with Syria.
The hotline -- or "deconfliction mechanism" as diplomats refer to it -- failed to prevent Russia's Ilyushin Il-20 military plane being shot down on September 17 by Syrian air defences.
Syria was responding to an Israeli strike, and Russia accused the Israeli pilots of using its larger plane as "cover" while only giving one minute of advance notice for their raid.
Israel strongly denied the Russian version of events.
In a further sign of the seriousness of the Russian reaction, Netanyahu convened a meeting of his security council on Tuesday to discuss the issue before flying to New York for the UN General Assembly.
He said afterwards that he had agreed with Putin to have Israeli and Russian military teams meet soon to enhance coordination.
- 'Only concern for now' -
But Israel sees the stakes as too high to accept severe limitations on its actions against Iran and Hezbollah in Syria, some analysts said.
Its pilots have already been trained to deal with the threat of the S-300, they say.
As for the Russians, they have not forgotten the 1970 battle when Israeli Phantom and Mirage planes destroyed Soviet MiGs stationed in Egypt in a matter of minutes, said Efraim Inbar, head of the Jerusalem Institute for Strategic Studies
Lerman does not believe the Russians are looking to escalate the situation, not wanting to compromise their gains in Syria.
But he believes that Russia will try to use the September 17 incident as a "bargaining chip in the larger game that they are playing with the United States and the international community."
Russian expert Vladimir Sotnikov also does not see a severe downturn in relations.
"Russia's only concern for now is to reach a settlement in the Syrian conflict because its armed forces are there," he said.
"Israel is a very important partner for Moscow. It is an ally of the United States, with whom Moscow wants to renew dialogue."