Operation Northern Shield, announced by the IDF on Tuesday morning and expected to last at least a month, is in reality just one stage in an ongoing Israeli effort to destroy Hezbollah tunnels under the Lebanese border.

It comes after technological and intelligence-gathering capabilities reached what the IDF terms “maturity”, leading to the next step: an overt digging operation to uncover and destroy the tunnels.

Hezbollah leader Hassan Nasrallah has previously threatened that, in a future war with Israel, his fighters would “conquer the Galilee”. The IDF believes that the tunnels are an integral part of that plan.

They were to be used for an initial surprise attack by Hezbollah’s elite “Radwan” fighters and also act as a supply-and-escape route for additional fighters, who would pour through breaches in the border fence.

On the Israeli side, they would attack both military and civilian targets, capturing soldiers and taking hostages.

The operation was approved by the cabinet a month ago but it was not launched immediately — for a number of reasons.

The greatest threat posted to Israel by Hezbollah is not this tunnel network but the arsenal of around 140,000 rockets, paid for by Iran, that the Shia militia holds in silos across Lebanon.

A factory where they plan to improve the accuracy of these missiles was mentioned recently as a likely target for an Israeli strike.

Destroying the tunnels, especially if some of the demolition work causes explosions on Lebanese soil, could lead to an escalation at a less-than-ideal time for Israel, when the situation in Gaza is also on a knife’s edge.

One of the reasons Israel rushed to agree to an Egyptian-brokered, Qatari-funded ceasefire with Hamas three weeks ago was to allow its security forces to focus on the northern border.

Not everyone agreed with that order of priorities. Defence Minister Avigdor Lieberman believed Israel should strike Hamas regardless of the deal. He argued that, left to its devices, it would become Hezbollah. But he was a lone voice in the cabinet and the IDF high command did not accept his opinion — so he resigned.

But there were different views among the military experts as to when the Hezbollah tunnels’ destruction would become imperative.

There were those who counselled no rush, because the tunnels were still months away from being operational.

But whether this was the best time to launch the operation and whether should it have gone ahead with high volume — including a media fanfare orchestrated by the IDF Spokesperson’s Unit and a prime-time statement to the media by Mr Netanyahu on Tuesday night — is hotly debated.

Some opposition figures claim it was timed to divert attention from the latest round of police recommendations, released on Sunday, to indict the prime minister for bribery,

They talk of “Operation Netanyahu Shield”.