Despite initial Israeli hopes that the crisis with Moscow that broke out after a Russian spy plane was shot down off the coast of Syria would soon die down, Russia’s military leadership has been ramping up tensions.

President Vladimir Putin had originally given the Israelis reason to believe the incident would be smoothed over, saying that it had been caused by “a tragic chain of accidents”, but in the following days Russia’s Defence Ministry has made a series of statements blaming Israel and announcing the supply of advanced air defence missiles to President Bashar al-Assad in Syria.

The only facts not under dispute is that, on the night of September 17, Israeli aircraft struck a target near Latakia, on Syria’s Mediterranean coast, close to an airbase used by Russia. In response, Syria launched missiles to shoot down the Israelis but instead struck a Russian Ilyushin Il-20 plane, which was on an intelligence-gathering mission. All 15 crew on board were killed.

Beyond that, the two countries’ accounts diverge.

The Israeli air force insisted the Russians were notified in advance and that Syria acted recklessly, firing more than 20 missiles in all directions, long after the Israeli aircraft had left the area.

But the Russian Defence Ministry in Moscow has presented a detailed account of how Israel had given insufficient warning, acted “unprofessionally” and put their plane in danger’s way.

At first, Israeli officials assumed the Russians were simply acting not to lose face over an accident caused by faulty co-ordination between them and their Syrian allies. But the Russian accusations intensified even after a delegation headed by the commander of the Israeli air force visited Moscow to share all the information Israel has on the incident.

Russia has announced plans to bolster its own defence systems in Syria with jamming equipment that will make further Israeli operations over Syria much harder.

More serious from Israel’s perspective is the plan to supply President Assad’s forces with advanced S300 air defence batteries. It is beginning to look like more than a face-saving exercise and Israeli officials are still unsure whether or not Russia is seriously planning to make life much more difficult for Israeli pilots as they pursue Iranian and Hezbollah targets in Syria.

Mr Putin has spoken twice with Prime Minister Benjamin Netanyahu on the telephone since the incident but has yet to speak publicly since his first remarks. His will likely be the last word on the matter.

For the moment, Israel is sticking to its story. Both Mr Netanyahu and Defence Minister Avigdor Lieberman insist they will continue operating against Iran in Syria but it is clear the operational parameters for Israel’s air strikes could now change.