The 2007 Arab League summit of heads of state in Riyadh this week appears to be the culmination of a major change in the way bitter foes perceive each other. As Palestinian Authority Chairman Mahmoud Abbas called upon the citizens of Israel to grasp a hand outstretched for peace, his prime minister, Hamas leader Ismail Haniyeh, listened impassively to the words of his president, without any outward signs of disapproval. At the summit, Hamas was formally accepted into the fold and had the mantle of Arab legitimacy thrust upon it. This latest rapprochement is part of a major trend spreading throughout the entire region. A hitherto unacceptable visitor gracing the event with his presence was Iranian Foreign Minister Manouchehr Mottaki; the twin Palestinian leadership of Abbas and Haniyeh met with him hours before the PA president addressed the summit. Apparently the meeting did not change one word in Abbas's presentation. The summit followed closely upon the recent conference on the stability of Iraq held in Baghdad, where Iran and Syria sat side by side with senior US, European and UN officials. There was no mistaking the fact that prominent members of the infamous "axis of evil," as proclaimed by US President George W. Bush just a few years ago, had become honorable tablemates engaged in serious discussions on resolving at least one of the core conflicts in the Middle East. The stakes have become so high that the necessity of attempting to ring in your enemy while confronting him in bloody battle on the ground has produced initiatives hitherto unimaginable. Days before the Riyadh summit, outgoing US Ambassador to Iraq Zalmay Khalilzad revealed in an interview with The New York Times that during 2006 he conducted an ongoing dialogue with leading figures in Iraq's Sunni insurgency. Nothing came of it, but the American official tried his best. The only significant element in the Arab world absent from Riyadh was al-Qaida, and one can only expect that they will denounce the summit and, of course, the Saudi peace plan, which was reaffirmed by all participants, without exception. The summit was preceded by the Mecca meeting, where the Fatah and Hamas movements agreed to form a national unity government. It was this new twin-headed administration that came to Riyadh. Immediately after the Mecca agreement was reached, it was publicly and viciously denounced by a senior al-Qaida spokesman as a Hamas betrayal of the Palestinian cause. It is more than plausible that al-Qaida understands the true significance of this latest Hamas change of tack better than non-Arab outsiders like us. On the day of the summit, Chief of General Staff Lt.-Gen. Gabi Ashkenazi briefed the Knesset on the continuing and ominous Hamas arms buildup in Gaza. They are massing for a fateful showdown, preparing for the worst of all options for them, he said. On the morrow of the summit, Israel has three principal options to choose from. The first is to beef up Abbas's forces in the forlorn hope that they will cow Hamas into submission. No one believes this is likely to work. The second is to enter Gaza in force and uproot Hamas's forces and infrastructure. This is doable, but at an incalculable price. It may be the only option in the end. But before going to this last resort, might we not test the waters, as the United States has done in Iraq and Iran, by trying to talk to our most bitter of enemies? On Wednesday, Hamas subscribed to the Saudi initiative, which contains many conditions that are unacceptable for Israel. Foremost among them is the demand to honor "the right of return" of the Arab refugees. But the initiative also states that the Arab states will offer Israel peace and normal relations. Hamas has signed up to this. Is this not already much more than the simple "recognition" that Israel has demanded? Before the boys go into the streets of Gaza and thread their way through the trenches, tunnels and bunkers that Hamas is feverishly constructing, should we not, at least, try the Khalilzad way and sound out our implacable enemy directly? The author is a former head of the Mossad and the National Security Council.