For the first time since the August 2014 cease-fire came into effect ending Operation Protective Edge, Hamas launched cross-border mortar attacks throughout Wednesday.

Hamas is targeting IDF units engaged in hi-tech tunnel detection work on the border between Israel and northern Gaza. It is escalating the situation due its fear that it is about to lose its trump card.

Hamas has invested much treasure and blood in its cross-border tunnel network, and its military wing is alarmed by what it perceives as one Israeli breakthrough after another in tunnel detection.

Although Hamas is keen on honing its rocket, drone and sea-based attack capabilities, its tunnel construction program remain its crown jewel.

During the two-month conflict in 2014, those tunnels terrorized civilians in southern Israel.

Hamas fighters popped up from seemingly nowhere to attack and kidnap soldiers.

The IDF responded to Wednesday’s stream of mortar shells with pinpoint tank fire at Hamas positions. Yet the cease-fire is now facing its first real challenge, and an escalation could easily occur in the near future. This is also a test of previous claims by defense officials of a zero-tolerance policy to Hamas breaches of the truce.