The Washington Post published an overview  today of the resources that Hamas puts into building tunnels to allow its operatives to infiltrate Israel, as well as Hamas’ strategy for utilizing the tunnels.
Describing this emerging “tunnel war,” a Palestinian militia document obtained by the news Web site al-Monitor said the objective of the underground network was “to surprise the enemy and strike it a deadly blow that doesn’t allow a chance for survival or escape or allow him a chance to confront and defend itself.” …
Analysts said the tunnels are a major prong of Hamas’s military strategy against Israel. The IDF has sussed out 36 of what it calls “terror tunnels,” but there are probably more. While the Gaza Strip remains mired in poverty — the 2011 per capita income was $1,165 — Hamas is thought to have sunk more than $1 million into the excavation and maintenance of every tunnel. “Much to the misfortune of the people of Gaza, Hamas has invested far more resources in ‘underground Gaza’ than in ‘upper Gaza,’” wrote al-Monitor’s Shlomi Eldar. “The ‘change and reform’ that Hamas offered its voters was invested in its tunnels at the expense of the people of Gaza.”
The Post cited an article in Al Monitor  published last October when Israel discovered a tunnel extending into its territory.
The Palestinian military sources, who asked to remain anonymous, told Al-Monitor that the tunnel was one of the largest military projects in recent years and a long-term endeavor intended for a military operation to be conducted when those who built the tunnel made the decision to launch it. This suggests that the tunnel may have been intended to kidnap Israeli soldiers or for a military attack against the Israeli army, discussed previously in Al-Monitor.
At the time, analysts believed that Hamas was looking to launch a “spectacular” attack  to boost its flagging fortunes.
In a related op-ed in the Wall Street Journal  (Google search terms ), former attorney general Michael Mukasey argued that a sustained attack on Hamas’s tunnel infrastructure would be a significant blow to the terror organization.
In his column today , The Times of Israel editor David Horovitz wrote:
What we are now starting to call “attack tunnels” are being discovered all the time — long, sophisticated underground passages, dug out over months, even years, running from under homes in the dense Gaza neighborhoods like Shejaiya within a mile or so of the border, and up under the Israeli side, some with multiple exits, some directed under the homes and dining halls at those kibbutzim and moshavim: Erez, Nir Oz, Nirim, Ein Hashelosha…
The number of such tunnels being found is rising all the time — five, eight, 13, 15. An immense investment by Hamas of time and money and energy and concrete and hatred. But we still haven’t found them all. Just this morning, Hamas terrorists were spotted emerging from yet another of their “attack tunnels”; the IDF released footage of some of the gunmen squirming away from the exit, en route to murder, before they were blown up. But not all the exits have been spotted in time; we’ve lost soldiers on the Israeli side of the border — where Israel has bolstered its troop deployment to find those exits, and to protect the local residents — gunned down by the Hamas infiltrators as they emerge.
While Israel aims to end the rocket threat from the Gaza Strip, the tunnel threat, in which Hamas has invested so much time, manpower and money, is the more immediate threat and has become the focus of Operation Protective Edge.
[Photo: idfnadesk / YouTube  ]