The New York Times has figured out that Hamas has been “[e]mboldened by the rising power of Islamists around the region” and is making use of its “increased clout” with the Muslim Brotherhood government in Egypt. Yes — news flash! — the Arab Spring is a disaster for Israel and for the cause of peace in the region.

In the short run, Israel faces a dilemma with a fast-approaching deadline. The government has called up thousands of reservists. At some point soon (given the disruption to civilian life) the government will have to decide to send these troops home or to push ahead with the ground attack.

The calculation on the ground attack is hardly straightforward. An old Middle East hand tells me, “There are real arguments for going in, but the down side is huge — in Washington, [the] EU, domestic politics, number of guys who will be lost, etc. And it may be that they have actually done enough — enough damage to Hamas, plus some Egyptian agreement not to permit Iranian missiles through Sinai.”

Indeed, there are a complex set of calculations that are likely known only to top Israeli officials.

First, Prime Minister Benjamin Netanyahu must decide, most likely within a day or two, how much the Israelis have been able to degrade Hamas forces from the air. There are, as one knowledge observer put it to me, “Two Gaza Cities — one above ground and one below.” It is the massive system of tunnels, literally big enough to drive a truck through, that is the most problematic. Have they destroyed all the Farj-5 missiles or are there more tucked away? And if so, where in the maze are the long-range missiles from Iran? Are they under schools and mosques? Would Israel get a significant number of these in a ground attack?

But then there are the medium-range missiles. Jonathan Schanzer of the Foundation for Defense of Democracies adds that Israel “cannot be seen as backing down from this fight while projectiles rain down on southern Israel.”

Another calculation is public opinion. At this point the Israeli public is strongly behind the prime minister. But after a week or two on the ground with mounting casualties that may change. And of course the patience of the “international community” and even the U.S. administration may be much more limited than the military timetable.

Yet another consideration is Egypt. It is unclear whether President Morsi is capable of or willing to shut down the massive smuggling of arms into the Sinai. Hamas would like a complete cessation of the blockade, an impossibility for Israel, especially with Morsi’s intentions and capabilities uncertain. Egypt, meanwhile, may have little concern about President Obama’s willingness to continue aid to Egypt, but Congress is a different matter. It was significant that on Sunday Sen. Lindsey Graham (R-S.C.) sounded more like Sen. Rand Paul (R-Ky.) when he declared, “Egypt, watch what you do and how you do it. You’re teetering with the Congress on having your aid cut off if you keep inciting violence between the Israelis and the Palestinians.”

And finally, Israel will have to decide how much time they can buy with Hamas. The last incursion into Gaza essentially got them 4 years of relative calm, but at a heavy price. If Israel can inhibit Hamas from continuing to shoot at civilians for 2 years with simply an air attack, is that preferable to a bloody land action that might only get it a year or two more of “peace”?

There are few answers and many conflicting reports. But do not expect Israel to cease its barrage and then let Egypt and Hamas chat about arms smuggling, as some news reports have suggested. For Israel, its main leverage over both Hamas and Egypt now is its air offensive. That still leaves the main question: Is the air offensive enough? We should know within a few days at most.

Read more from The Washington Post:

Eugene Robinson: In Gaza conflict, neither side knows what’s next

Richard Cohen: Hamas’s callousness puts its own people at risk