Ever since the Trojans welcomed the Wooden Horse, full of armed Greeks, into their city, rulers and regimes have unintentionally defeated themselves. But as the last month has made obvious, with the rule of Hamas in Gaza we have something else entirely: not folly, but a strategy designed to inflict self-harm. The clearest, but by no means the only example of this is the fuel crisis that has brought transportation in Gaza to a virtual standstill. Even as it harshly condemned the Israeli "siege" of the Gaza Strip, Hamas acted to exacerbate the problem by repeatedly confiscating fuel trucks and carrying out attacks on border crossings. On April 9, it launched an assault on the fuel terminal at Nahal Oz, which provides gas and fuel to the residents of the Strip. Last week, Hamas militiamen attacked trucks heading toward the Nahal Oz crossing that carried fuel intended for the UN Relief and Works Agency (UNRWA) and hospitals in the Gaza Strip. And the IDF was forced on Sunday to halt deliveries through the Karni crossing after vehicles came under Palestinian mortar fire while attempting to deliver food and fuel to Gazans. Hamas, of course, does not have a monopoly on such self-harm; in one form or another, the tactic is shared by all terrorist movements, including the intifadas that brought such ruin to the Palestinian population. How then are we to understand such self-defeating behavior? There are two ways, as political scientist James Q. Wilson has said, of thinking about terrorism. One is to see terrorism as an extreme expression of underlying injustices, and to assume that if the root problem is solved, the symptom will disappear. The second, and more realistic, is to understand that whatever the underlying injustice, there are terrorists who by their very nature oppose solutions that would remedy that injustice. Any reform or amelioration, short of destroying the state, threatens their raison d'etre. THIS LESSON must guide Israel's response to Hamas's offer of a truce. Khaled Mashaal, the group's Damascus-based leader, said Monday that his movement would offer Israel a 10-year hudna if it withdrew from all areas it captured in 1967. Gaza-based Hamas representatives Mahmoud Zahar and Saeed Seyam have been in Cairo as part of Egyptian mediation efforts toward a cease-fire. The problem with such offers is not merely that Hamas would use a truce to rearm and regroup. Mashaal himself, after all, has proclaimed as much. "It is a tactic in conducting the struggle; it is normal for any resistance that operates in its people's interest... to sometimes escalate, other times retreat a bit," he said in a recent interview with Al-Jazeera television. Nor is it merely that the offer is accompanied by further threats of violence. Hamas has warned of an "unprecedented escalation" against Israel if it does not agree soon to the cease-fire offer, the London-based Asharq Al-Awsat reported Sunday. It is also an offer that exploits both Israel's justified fear of further terrorist attacks and our sense of concern vis-Ã -vis Gaza's growing humanitarian crisis. The real problem, however, is that here too, Hamas's aim is not to reach a lasting resolution to the conflict, but precisely to exacerbate it - to weaken the Israeli adversary and foster the illusion that the next set of concessions will be the last. "To subdue the enemy without fighting is the acme of skill," Sun Tzu said in the 4th century BCE. IN INTERNATIONAL relations, as in other dimensions of life, the good intentions of others alone cannot aid those who refuse to help themselves. As the US is now learning in Iraq, for instance, democracy cannot be imposed on Arab societies from without. Much as Israel may wish for progressive reforms in Palestinian Arab society and for the concomitant relief of Palestinian suffering, such salvation need come from within. Civilized nations are in an unenviable position when confronting regimes dedicated to the tragic ethos of self-harm. In the case of Hamas, the best approach remains continued adherence to the Quartet's policy of no contact with Hamas until it accepts the international community's three conditions for engagement: recognizing Israel's right to exist, renouncing terrorism and accepting previous Israeli-Palestinian agreements.