Trying to distinguish between the good guys and the bad in the latest bout of Gaza fighting is bit like trying to decide who to hire as a babysitter - the Boston Strangler or Jack the Ripper. Hamas may have been elected fair and square, yet its true orientation is totalitarian. No surprise, then, that it has been using the cease-fire with Israel, in effect since June 16, not only to prepare for the next round against the Jewish state, but to smother rival factions. Thus Hamas shut down the Gaza offices of the Ma'an news agency (an outfit funded largely by Denmark) as well as the Sha'ab radio station, run by the Popular Front for the Liberation of Palestine. Even Islamic Jihad has been put on notice to watch its behavior. It's not as if Hamas faces much opposition. Perhaps its most significant challenge comes from the Dughmush clan, which enriched itself by smuggling weapons and contraband through tunnels dug under the Philadelphi Corridor into Sinai, and the equally lucrative hostage-taking business. Clan leaders help found the Popular Resistance Committees, a terror group active in the second intifada and probably involved in capturing Gilad Schalit. It would not be surprising, therefore, to discover that Dughmush was behind the July 25 car-bombing along the Gaza beachfront which killed five Hamas operatives, injured scores of passersby and took the life of a little girl. If so, expect his clan to be the next Hamas target. FOR ITS OWN Machiavellian reasons, Hamas blames exiled Fatah strongman Muhammad Dahlan for the bombing. On Saturday it went after the Hilles clan, described by the media as "loosely affiliated with Fatah movement." Hamas cut off the clan's Gaza City stronghold. In the ensuing fighting, nine Palestinians were killed; a residential building was reportedly blown up, with people still in it; and Hamas sharpshooters aiming from minarets in nearby mosques targeted anyone trying to flee. Hamas even used tunnels dug in the area - originally for use against Israel - to surprise the clan. At least 100 people were injured, including a dozen children. Many more were taken into Hamas custody. Under withering Hamas fire, about 180 members of the clan, led by headman Ahmed Hilles, sought to enter Israel via the Nahal Oz crossing, leaving their women and children behind. At the request of Egypt and the Palestinian Authority - and as a humanitarian gesture - Israel allowed the Hilles men in, with the intention of sending them on to Mahmoud Abbas's Ramallah headquarters. But in the murky world of Palestinian politics, relationships are seldom straightforward. Far from being Dahlan stooges, the Hilles had actually tried to assassinate Dahlan, together with Abbas, in November 2004, shortly after Yasser Arafat died and Abbas went to Gaza to receive visitors in Fatah's mourning tent. Abbas and Dahlan survived, but two of their bodyguards didn't. Yesterday, after the dust had settled, Abbas did an about-face: At his request, Israel "repatriated" to Gaza many of the men who had sought his protection in Ramallah. ISRAEL AND the West would do well to internalize, given this internecine Palestinian violence, that Hamas's rule in Gaza is the best indicator to date of how Palestinians would run their affairs in a fully independent Palestine. We need also to recognize the failure of institution-building and due process in the Abbas component of the PA thus far, as illuminated by the torture of Hamas functionaries, on Fatah's behalf, by the Aksa Martyrs Brigade. Dismally, despite the brutal nature of its Gaza rule, Hamas remains more popular in the West Bank and Gaza than Abbas. This ongoing triumph of bellicosity and intransigence over relative moderation is greatly assisted by Abbas's abject failure to root out corruption from Fatah. In such a climate, there aren't enough checkpoints in the West Bank Israel can dismantle to "help" Abbas. Indeed, IDF pullbacks and eased security conditions in the West Bank would simply set the stage for a Hamas takeover and leave Israel more vulnerable to terrorism. Plainly, lifting international sanctions on Hamas would be a flagrant reward for Islamist violence and tyranny. At the same time, Hamas is a permanent fixture in Palestinian politics. Rather than closing its eyes to this reality, Israel must more thoroughly integrate awareness of it into its security and diplomatic strategy.