Is a new Middle East war on Israel's horizon?
Looking out from Israeli-held territory, the scrubby and rock-strewn ground pitches steeply downwards towards a patrol road and the border fence.
The current frontier with Syria - the young lieutenant points out - is about a third of the way up the opposite escarpment. And just a couple of kilometres beyond that is another ridge, which is Jordan.
This is Israel's front line with Syria. The Syrian army was evicted from the Golan Heights when Israeli forces captured it in the 1967 Middle East war.
Israeli law was extended there in 1981 - effectively annexing this crucial strategic high ground. It is now a heavily fortified area.
We pull up alongside a platoon of Merkava tanks, key sensors and weaponry shrouded in tarpaulin covers against the winter damp.
Once things were fairly simple here. Israel faced the Syrian army across the ceasefire demarcation lines, monitored by UN observers.
But there was almost no need for them. This was Israel's most peaceful frontier since 1973. But the civil wars in Syria and the collapse of Syrian government control in many areas have changed all that.
'Closer than ever'
The geography here is not the only thing that is complicated. The war in Syria has altered the strategic map as well.
Opposite the southern Golan the ground is held by a local force - the Yarmouk Martyr's Brigade - which owes its allegiance to so-called Islamic State. Israeli troops see its fighters exercising and monitoring their positions, but there is rarely trouble.
What alarms Israel most is what is happening further north, with the victory of Syrian government forces backed by Iran and Tehran's ally, the Lebanese Shia militia group, Hezbollah.
Professor Asher Susser, a senior fellow at the Center for Middle Eastern Studies at Tel Aviv University, summed it up in one sentence.
"The changes in Syria," he told me, "have brought Iran closer to Israel's borders than ever."
He told me that at least in theory it creates "the possibility of Iranian-Hezbollah co-operation not only along the border between Israel and Lebanon but along the border between Israel and Syria as well".
In his view there is "a dangerous potential for a long border from the Mediterranean, across Lebanon and Syria, with Hezbollah and Iran at very close quarters with Israel.
"Israel," he stressed, "has never faced that kind of situation on its northern border before."
So what exactly is Tehran's goal in Syria? For an answer I turned to Ehud Yaari, veteran Middle East commentator for Israel's Channel 2 Television News.
"The strategic objective of the Iranians today," he told me, "is to establish a land corridor between Iran and Hezbollah in Lebanon; to reach the Mediterranean and the Israeli frontier."
This land corridor, he explained would go "from Iran via the Shia regions of Iraq, through the western Iraqi desert, linking up with Assad and Hezbollah.
"This," he stressed, "is strategically the major threat to Israel today".
Iran of course is not the only foreign country involved in the fighting in Syria.
Russian air power - along with Hezbollah fighters and other Shia militias on the ground - played a decisive role in propping up the Assad regime.
Russia has twice announced the scaling down of its military deployments, but actually shows every sign of being in Syria to stay.
The presence of Russian aircraft and especially long-range radars and air defence missiles greatly complicates the threat environment facing the Israeli air force.
It has struck at arms shipments going from the Syrians to Hezbollah on several occasions, having set a "red line" that rejects the transfer of sophisticated missile systems to the Shia militia.
Ehud Yaari told me that the presence of the Russians has not significantly affected the Israeli Air Force's freedom of action over southern Syria.
"There is an understanding," he explains, "a sort of a hotline between Israel and Russia where a Russian-speaking Israeli Air Force officer and a Russian officer in Syria are co-ordinating and making sure that you don't have any mishaps."
This arrangement, he insists, is working and this is fundamentally because the Russians' strategic interests and those of Iran are very different.
Mr Yaari says that the Russians are not very interested in protecting Hezbollah arms shipments or the security situation south of Damascus, close to the Israeli border.
How big a threat is all of this to Israel? A series of military briefings suggests that Hezbollah and its growing armament is seen as perhaps the primary challenge to Israel's security.
Hezbollah, due to its training and equipment, is now viewed as a fully-fledged army rather than a semi-amateur militia.
"It has lost heavily in the Syrian fighting but it has also gained invaluable combat experience," a brigadier told me.
It has established a well-entrenched infrastructure in southern Lebanon with a huge arsenal of missiles of varying ranges.
The fear among Israeli military experts is that under Iranian tutelage it might seek to establish a similar platform for operations in Syria as well.
There is a precedent here as Ehud Yaari explains.
"The major concern now is that the Syrian regime will be able to negotiate deals with the different factions of the rebels in the southern region of Syria so that they withdraw from border areas.
"This," he says, "is exactly what happened in other areas of Syria, especially in the countryside around Damascus."
Such a move could open the way to the entrenchment of Hezbollah, Iranian Revolutionary Guards or other Shia militias sponsored by Iran in the south.
At present this is more a potential rather than an actual threat.
Professor Asher Susser told me that, in the long-run, much depends upon how the Russians play the game of regional alliances.
"If the Russians and the Turks are on one side of the equation and the Iranians on the other," he told me, "that may put a limit on what it is that the Iranians can achieve."
This is why he believes that Israel's contacts with Moscow are so important.
"This," he told me, "is a relationship that Israel's Prime Minister Benjamin Netanyahu has reinforced over the last year or two.
"Mr Putin and the Russians," he says, "have an understanding of Israel's strategic needs which, if they take them into consideration, may put a brake on this Iranian-Syrian project."
Nobody knows when or how the fighting in Syria will end. Several Israeli experts I spoke to hope for some kind of regional deal that might constrain the freedom of movement of Iranian-backed militias in Syria.
But agreement or not, the new actors on Israel's frontiers present a new and more complicated set of challenges.
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