When Lt.-Gen. Benny Gantz took up his post as Israel’s 20th chief of General Staff in mid-February, the Egyptian revolution had only recently succeeded in toppling Hosni Mubarak – and concern was mounting in Israel over a possible takeover by the Muslim Brotherhood.

That concern has not disappeared, and will likely manifest itself in the new multiyear plan that Gantz quickly drafted since taking office, to be presented next week to the cabinet for approval.

But like many of his predecessors, Gantz has found himself facing a far more immediate threat from the Gaza Strip.

The escalation in violence along the border, that continued Sunday with an antitank missile that was fired at an IDF Merkava tank, dates back to last Wednesday when the IDF, “in a rare move,” struck a Hamas position, killing two Hamas operatives, in retaliation for a rocket strike earlier that day.

The strike on Wednesday was rare for two reasons.

First, it was carried out in the middle of the day when, hitherto, most retaliatory attacks by the IDF to Palestinian rocket fire had taken place at night.

Second, the target chosen was a manned Hamas position – when, until then, it had been possible to count the number of Hamas operatives killed by the IDF in airstrikes since Operation Cast Lead on little more than one hand.

The IDF chose this target to try to teach Hamas a lesson that would lead it to crack down on other groups, like Islamic Jihad, which has been behind most of the terrorist activity coming out of Gaza since Cast Lead.

It did not work. Instead, the attack pushed Ahmed Jabarai, leader of Hamas’s military wing, to strike back directly at the weekend with some 50 mortar shells on IDF bases, and western Negev communities.

Where this is all headed is still unclear.

The IDF believes that despite the return to so-called direct involvement in terror, Hamas still prefers not to get into a fight with the IDF, as it seeks to obtain more weaponry and greater military capabilities.

But this current cycle of violence is likely an indication that the deterrence Israel created following Cast Lead has begun to erode. As a result, it will likely be just a matter of time before the IDF is sent back into Gaza. This could take weeks, months – or even up to a year – but the sense is that such a conflict is inevitable.

A future operation in Gaza, however, will probably be far different to the last one in 2008-09. Hamas has learned many of the necessary lessons from its failures during Cast Lead, and is investing in longer-range rockets, anti-tank missiles, improved improvised explosive devices and better command-and-control systems.

It is however not the only group doing so.

Islamic Jihad is also improving its military capabilities, and is seeking a more independent role in a future battle against Israel. If, during Cast Lead, Islamic Jihad fought mostly under Hamas command, in a future conflict it will have its own units and field commanders.

Islamic Jihad is already known to have an arsenal of long-range Grad-model Katyusha rockets – its operatives fired the two Katyushas last month into Beersheba. It also might have some anti-tank missiles.

The weaponry that was captured aboard the Victoria cargo ship by the Navy last week was destined for Palestinian terrorist groups in Gaza – possibly Hamas and possibly the Islamic Jihad.

In the meantime, Israel’s strategy is to try and restore its deterrence – or at least maintain what is left for as long as it is possible – to stave off another conflict.