(photo credit: AP [file])
Although the death of Roni Yihye in a Kassam attack on Sderot Wednesday was this week's most tragic event, it was Thursday's direct strike by a Grad missile on an Ashkelon apartment building - even though it resulted in no serious injuries - that was by far the most worrying development in the Gaza situation.
This was not the first time that a modified Grad 122-mm was fired from Gaza at nearby Israeli communities. Hamas and Islamic Jihad first began launching the Soviet-manufactured missile two years ago, although until now these were sporadic incidents involving only one or two missiles.
This indicated the relative scarcity of the weapon in Gaza - which had to be smuggled in through or under the Egyptian border - and the difficulties involved in launching it from the northern section of the Strip so it would have a sufficient range to hit the heart of Ashkelon.
The fact that terror groups were able to fire up to 10 Grads at Ashkelon on Thursday demonstrated the new and far more dangerous strategic situation that now exists in the southwest corner of the country.
The breach in the border fence with Egypt last month has clearly allowed Hamas and Islamic Jihad to bring in a far more substantial stockpile of the weapon, as well as personnel who have been professionally trained abroad (in Iran, Syria or Lebanon) to effectively modify and launch the missiles.
What's more, the ability of these groups to now fire off multiple missiles in a relatively short time period indicates another significant technological advancement.
Hamas and Islamic Jihad still don't have the kind of mobile launch vehicles used by Hizbullah during the Second Lebanon War that can launch 40 such missiles in 20 seconds; and even if they did, these would be far more vulnerable to Israeli Air Force fire in the relatively open Gaza landscape than they were in south Lebanon.
But as the IDF reported earlier this month, the Gazan groups have become more adept at building compact underground rocket silos and trenches from which they can launch Kassams and Grads by remote control, thus increasing their ability to get off multiple shots without risking direct Israeli counterfire.
This ability to launch a quick concentrated wave of missiles helps compensate for the main drawback of these weapons: their lack of accuracy.
With a range of up to 30 kilometers and the ability to punch through a concrete roof or wall before detonating, the new Grad threat - together with the increased capability of the latest generation of locally manufactured Kassam rockets, some of which can effectively cover the dozen kilometers from Gaza to Ashkelon - now puts that city's population of over 100,000 at a risk comparable to that faced by Sderot over the past seven years.
Hamas and its allies in Gaza have clearly raised the strategic stakes; the question now is how Israel is going to respond.
The immediate answer, as indicated by yesterday's IAF strike near the home of Ismail Haniyeh, together with Internal Security Minister Avi Dichter's comments in Sderot, suggest that for the time being, targeted killings of the Hamas political leadership is the preferred option to a large IDF incursion inside Gaza.
This was the strategy pursued effectively during the second intifada, when such figures as Ahmed Yassin and Abdel Aziz Rantisi were killed by Israeli air strikes.
But that was when the main threat posed by Hamas was its horde of suicide bombers and its still relatively crude stash of Kassams.
Even if Israeli security forces were able to halt the current rocket attacks by means of deterrence - be it in the context of a Hamas "cease-fire" or some other arrangement - that would do nothing to degrade or impede the growing strategic danger to Ashkelon and other Israeli communities that could easily be activated at a future date.
The potential risks of an IDF invasion of Gaza are now substantially higher than they were before Hamas was armed with anti-tank weapons, mines, bunkers and possibly even anti-aircraft rockets.
But political considerations, and not military factors, are now holding back such an operation. Without a viable "exit strategy" and at least some support from Israel's key ally, the United States, the Olmert government clearly prefers to leave sending in the troops as a last resort.
After a week such as this, though, that option now looks more than ever like simply a matter of increasingly reduced time.