“We responded with massive artillery fire,” a military source from the Northern Command told The Jerusalem Post on Sunday, shortly after a barrage of Katyusha rockets was launched at Israel.The use of the word “massive” was a reference to the dozens of artillery shells directed at the southern Lebanese area from which the rocket attack stemmed. The source was keen to underline the fact that this was not an ordinary retaliatory strike.Although the military has not yet been able to determine who is behind the rocket attack on Kiryat Shmona’s residents, one possibility is radical Sunni pro-al-Qaida elements – the same type of terrorists who rocketed northern Israel in August, prompting an Israeli air strike south of Beirut last summer.The point Israel was making with its artillery shells – beyond hoping to hit those who attempted to murder Israelis – was that the identity of the attackers will have little bearing on the response. It is up to the governments sovereign over areas used as staging grounds for terrorism to prevent incidents that have the potential to escalate violence.This is a continuation of the message sent by Israel to Hamas in Gaza last week, through a large military strike in response to a deadly cross-border shooting that claimed the life of a Defense Ministry employee. It is the same message broadcast by Israel days later, in the form of air strikes on a weapons factory and arms storage site in Gaza, following rocket attacks on southern rural communities.The use of precision guided Tamuz surface-to-surface missiles to destroy Syrian army positions that fired on Israel in the past is part of the same pattern. After each of these responses, the borders fell silent again for a time.The warning is also directed at larger enemies like Hezbollah, and those who try to arm it with deadly weapons for use against Israel in a future clash.At some point, Israel’s warnings may be disregarded, and the IDF is preparing itself for just such a day.