History is repeating itself in the Palestinian territories. Washington refuses to engage a right-wing Palestinian group – and so spawns organizations that are even more extreme.

It happened in the 1980s, when the US balked at recognizing the Palestine Liberation Organization (PLO) and hesitated to seek a resolution to the Middle East conflict through the creation of a Palestinian state. Those long delays helped propel the rise of the hard-line Islamist party Hamas.

Today, the lack of US dialogue with Hamas and the group's moderation are leading to the formation of new, more dangerous rejectionist groups.

If the US were serious about engaging Hamas, it would acknowledge three things:

1. By agreeing to accept a state in the West Bank and Gaza, Hamas is demonstrating de facto recognition of Israel.

2. Hamas has said Palestinian Authority President Mahmoud Abbas can continue negotiations with Israel, and that it would abide by any peace agreement he signs if it is ratified by a referendum of the Palestinian people.

3. Hamas has observed several cease-fires with Israel and has offered decades-long truces in exchange for an Israeli withdrawal from the West Bank and Gaza.

In December 1988, President Reagan authorized dialogue between the US government and the PLO – 14 years after the Arab League designated the PLO the "sole legitimate representative of the Palestinian people," and 13 years after the United Nations General Assembly made the PLO an observer organization. Even Mr. Reagan's step conferred no official US recognition, though the PLO had some form of relations with at least 70 countries and was widely recognized by the Palestinians as their legitimate political leadership.

Reagan's decision came one year after the founding of Hamas, established as an Islamic armed force to counter Israel at the beginning of the first Palestinian uprising in 1987. Hamas's political platform calling for the destruction of Israel was in part a response to the gradual moderation of the PLO, which adopted the position of accepting a Palestinian state in the West Bank and Gaza in 1988.

Back then, Hamas gave new voice to the rejectionists, while centering itself ideologically in the budding Islamic political revival that flowed from the Iranian revolution and the successes of the mujahideen in Afghanistan.

And now it appears that though Hamas's charter remains the same, like the PLO before it, Hamas has moderated its views substantially. In a July 31 interview with The Wall Street Journal, Hamas leader Khaled Mashaal reiterated acceptance of a Palestinian state in the West Bank and Gaza on the 1967 lines. "This is the national program. This is our program."

But, as with Hamas's rise to the right of the PLO in the late 1980s, new rejectionist groups are springing up with ideologies far more dangerous and fundamentalist than those of Hamas.

On Sept. 6, the Saudi newspaper Asharq Al-Awsat reported on a Palestinian, Mahmud Talib, who is on the run from Hamas security forces inside Gaza. According to the article, Talib had been a leader in the Hamas military wing, but split from the organization in 2006 when Hamas decided to participate in Palestinian elections, a key signal of its new openness to a two-state solution. Hamas accuses Mr. Talib of masterminding recent bomb attacks in Gaza targeting Hamas security forces.

Talib and his supporters report planning to pledge their allegiance to Osama bin Laden. Talib also claims to have been involved in alleged assassination attempts in Gaza against former President Jimmy Carter and former British Prime Minister Tony Blair, now Quartet Middle East Envoy. In recent months the Israeli press has also reported on defections from Hamas and the formation of Al Qaeda-inspired organizations in Gaza.

Such groups have claimed responsibility for attacks against Israeli forces on the Gaza border, at a time when Hamas is observing a de facto cease-fire.

While Palestinians attacking Israel is not new, the rise of groups in the Palestinian territories espousing a Salafist (fundamentalist Sunni) ideology is. Though Hamas initially attempted to accommodate these organizations, relations have clearly soured.

On Aug. 14, clashes between Hamas security forces in Gaza and another Al Qaeda-inspired faction, Jund Ansar Allah, left 24 people dead.

The distinction between Hamas and Al Qaeda is significant. Both have been responsible for horrific acts of terrorism, but Hamas is a domestic Palestinian organization, which has consistently avoided attacking non-Israeli targets. Its ideological roots are less conservative than Al Qaeda's, and, since 9/11, Hamas has distanced itself from Al Qaeda's rhetoric and global attacks. In the past few years, Hamas has also shown substantial willingness to compromise; Al Qaeda has not.

The US should not overestimate support in Gaza for these more radical organizations. Compared with members of Hamas or the PLO factions, their numbers are few. Gaza is not a new base for global Al Qaeda attacks. But the longer Gaza is left isolated and impoverished, the longer the Hamas government cannot provide hope for the people of Gaza, the more likely it is that Al Qaeda's ideology will gain support.

The long delay in US outreach to the PLO contributed to the rise of Hamas, and now the delay in engaging Hamas is encouraging the growth of Al Qaeda-inspired organizations on the eastern Mediterranean.

This is yet another reason for the West to talk to Hamas.