Israel claimed on 9 February that an Iranian unmanned aerial vehicle entered Israeli airspace and was shot down. In response, Israeli aircraft carried out strikes on targets in Syria, in the course of which an Israeli F-16 fighter aircraft was brought down.

• The launching of an Iranian unmanned aerial vehicle into Israeli airspace (the first such incident recorded) was likely a test of Israeli reaction.
• The scale of Syrian air defences' response to the initial Israeli air strikes was unprecedented and probably reflects Syria's longstanding strategy in its civil war of drawing its backers into ever greater support by escalating against its enemies.
• This dynamic indicates a rising risk of war that would see significant damage to Israeli infrastructure and residential areas, as well as crippling damage to Lebanese and Syrian infrastructure and government targets.

Israel claimed that the unmanned aerial vehicle (UAV) was Iranian-manufactured and was launched from the Tiyas Air Base (T4 airbase) in Syria's Homs governorate. The UAV was allegedly shot down by an Israeli helicopter; however, the Iranian and Syrian authorities denied any incursion into Israeli air space. Israel retaliated by carrying out airstrikes on the T4 airbase. Israeli aircraft were engaged by what appears to have been dozens of anti-aircraft missiles. One Israeli F-16 fighter aircraft was brought down, with its pilot and co-pilots ejecting inside Israeli territory. Israel responded to the downing of the aircraft by attacking 12 additional targets in Syria. These included four unspecified Iranian military bases and three Syrian air defence bases. Israel claims that almost half of the Syrian army's air defences have been destroyed. The Israelis have since attempted to draw a line following their latest airstrikes, reportedly following a call by Russian President Vladimir Putin to Israeli Prime Minister Binyamin Netanyahu.

These incidents came after Israel and Lebanon had been exchanging threats. Israeli Defence Minister Avigdor Lieberman said on 31 January that Lebanon's awarding to Total, Eni, and Novatek of oil exploration rights to Block 9, contested between Israel and Lebanon, was "provocative" and "challenging". In the same speech, he said that there would be a full-scale war if Lebanese Hizbullah forces attacked Israel. Separately, Israel has begun construction of a new border wall on the border with Lebanon, which Lebanon claims is on Lebanese territory. On 7 February, the Lebanese government ordered the Lebanese Armed Forces (LAF) to stop Israel from making any incursions into Lebanese territory. A third potential source of conflict is Israel's declaration, first made in July 2017, that it would not allow Iranian-sponsored building of missile or other advanced weapon factories for Hizbullah in Syria or Lebanon. A Kuwaiti newspaper, al-Jareeda, claimed on 4 February that Iran was going ahead with these plans and was finding new possible locations for a factory.

Syrian risk-taking

Syria's bringing down of the Israeli jet seems to have been accomplished by firing an unprecedentedly high number of surface-to-air missiles. Syrian responses to Israeli airstrikes had previously been perfunctory, intended to ensure that Israel would not view the Syrian reaction as an escalation and treat it as a casus belli. The launching of a UAV from a Syrian base far from the sensitive border area of the Golan demonstrates that Iran can target Israel without necessarily violating Israeli demands that any bases of "foreign forces" in Syria are kept well away from Israel's bases. (The presence of such forces west of the Damascus-Suwayda road has been declared a 'red line' by Israel.) The launching of the UAV at a time of increasing regional interstate war risks indicates that Iran is willing to accept greater risk of war between Israel, Lebanon, and Hizbullah.

Outlook and implications

The more Iran expands its and its proxies' military influence in Syria, the more likely war becomes. The Iranian launch of a UAV to demonstrate its reach and the scale of Syria's response to the initial Israeli airstrikes both indicate an increased tolerance of interstate war risk on the part of the Iranian axis. The next war would be likely to involve not only Hizbullah and Israel, but also Syrian government forces, to the extent of their very limited capacity, resulting from their priority commitment to the civil war and combat fatigue.

We assess that Israel's military strategy is still to delay a war as long as possible, while maintaining the Israeli air force's freedom of movement to collect intelligence over both Lebanon and Syria. The Israeli military spokesperson was quick to declare that Israel had retaliated sufficiently and would not escalate further. This reflects Israel's concern that a future war would cause severe damage to its key infrastructure, including airports and ports, especially Haifa, and that it would cause extensive property damage in residential and industrial areas in northern Israel. Hizbullah is likely to target offshore facilities in northern Israel, although Israel has deployed naval assets to protect these. Offshore energy assets near Ashdod are unlikely to be affected.

In the event of war, Israel would be likely to strike at Syrian air defence and ground forces, as well as airports and military factories. In Syria and Lebanon, Israel is also likely to attack dual-use and civilian infrastructure, such as roads, warehouses suspected of storing rockets, factories, electricity generation facilities, energy storage facilities, airports, and ports. Unlike the 2006 war with Hizbullah, the Lebanese state, its infrastructure, and its armed forces are likely to be treated as hostile by Israel from the outset, given Hizbullah's role in government and its dominating influence.