It's no coincidence that tensions between Israel and both Hizballah and Hamas are escalating. Israel confronts these militant Islamist movements on two of its borders. Their activities are closely linked to Iran's aggressive drive to expand its regional influence and Syria's role as henchman.

Yet there are three key differences between these organizations that are relevant to Israel's dealings with them. First, one is Shi'ite Muslim, the other Sunni. This determines important variations in their relationship with the rest of the Arab and Muslim world, with the Shi'ite Hizballah more closely linked to Iran and the Sunni Hamas more likely to be influenced by the rest of the Sunni Arab world, led by Saudi Arabia and Egypt.

Second, Hizballah is more inclined to expand its struggle beyond the borders of Israel, whereas Hamas has never done so. Hizballah attacks worldwide are particularly likely now, in the aftermath of the Imad Mughniyeh assassination in Damascus and in view of Hassan Nasrallah's explicit threats to that effect.

And third, Hizballah refuses to negotiate political issues with Israel. It agrees to discuss prisoner exchange via third parties, but nothing more. It is also part of a state, Lebanon, with which Israel has on occasion had direct dealings, and Hizballah itself no longer shares a border with Israel. Important leaders within Hamas, on the other hand, periodically advertise their willingness to discuss a ceasefire with Israel, whether short-term (tahdiyeh) or long-term (hudna)--in addition to prisoner-exchange talks via a third party, Egypt, that parallel those with Hizballah. Hamas is also in control of a finite, state-like territory, the Gaza Strip, that borders directly on Israel.

These differences between Hizballah and Hamas point to the possibility of an Israel-Hamas political dialogue. But the remaining circumstances do not, for one because Israel's negotiations over a final status peace agreement with the more moderate Ramallah-based Palestinian leadership would be prejudiced by the advent of parallel ceasefire talks with Hamas. The latter would ostensibly present Palestinians with an alternative and "cheaper" model of coexistence with Israel.

Then too, Hamas does not speak with one voice: there is no clear and authoritative interlocutor in Gaza or Damascus with whom Israel or Arab mediators in Cairo and Riyadh can deal. And finally, the Hamas version of a ceasefire, to the extent it has been transmitted to us, is problematic. Hamas apparently attaches to a long-term hudna the same demands regarding borders, refugees, Jerusalem, etc., that the PLO makes in return for genuine peace. Meanwhile, either a hudna or a tahdiyeh almost certainly leaves the Palestinian Islamist movement free to continue its armed buildup in Gaza and to maintain its ideological demand that (eventually) Israel cease to exist--thereby merely postponing an armed confrontation until such time as Hamas and its allies feel better prepared.

Today we confront a newly fluid situation in Gaza created by the recent Hamas breach of the border with Egypt and the PA demand to take over all Gaza border crossings in coordination with Israel, Egypt, Hamas and the EU. This has given fresh impetus in some circles to the option of talking to Hamas about a new modus vivendi. At the same time, the new situation is itself a product of the escalating military encounter between Hamas and Israel and the latter's growing reliance on both economic sanctions and targeted assassinations of senior terrorists in Gaza.

These tactics, plainly unsuccessful in deterring rocket attacks on southern Israel, fall somewhere between the more clear-cut options of talking to Hamas and reoccupying large parts of the Gaza Strip. That may be one reason why Israelis are losing patience after seven years of Hamas rocket attacks: witness the new political activism of the residents of Sderot, demonstrating against the government in Tel Aviv and Jerusalem.

Here we come full circle back to the Hizballah link. If Israel now chooses to escalate its military offensive against Hamas and reoccupy parts of the Strip, it must take into account the possibility that Hizballah will again launch a rocket war against Israel from Lebanon. This would reflect not only Iranian and Syrian-inspired solidarity with Hamas and not only a way for Hizballah to escape the Lebanese domestic crisis it helped create. It would also be an expression of revenge for the Mughniyeh assassination that Hizballah insists Israel perpetrated.

We're left with good reasons neither to talk to Hamas nor to reoccupy the Gaza Strip. Yet something has to give. Remember Eli Wallach in "The good, the bad and the ugly"? "If you wanna shoot, shoot; don't talk". We still haven't decided.-