Some Hamas officials say Yassin's death is part of a war against Islam
"Ahmed Yassin was the Palestinian Bin Laden," said the Israeli defence minister, Shaul Mofaz, after Israel assassinated the Hamas spiritual leader.
It was an obvious attempt to equate the killing with the US-led war against the al-Qaeda Islamic militant network blamed for the 11 September attacks in New York and Washington in 2001.
World leaders were not convinced.
The European Union and the UN Secretary General, Kofi Annan, denounced the killing as illegal and dangerous, something they probably would not have done were the victim Osama Bin Laden.
Clash of civilisations
So where does Hamas fit into the "global war on terrorism"?
Is it cut from the same cloth as al-Qaeda, or is it a different kind of radical Islamic group?
Al-Qaeda is generally viewed as a global movement. It has its roots among Arabs who received military training from the CIA in the 1980s and forged ties during the war against the Soviet occupation of Afghanistan.
Its aim: Apparently to encourage a clash of civilisations between the West and the Muslim world.
Palestinian grief and anger at the killing is deep
Its tactic: To target the US and Middle Eastern regimes that are allied to it, hoping to draw a crushing response that will widen the breach between them and strengthen a radical Islamic identity as a separate political and military force.
It is not clear how much al-Qaeda still exists as an active network, but this, at least, is its ideology.
Hamas is a Palestinian nationalist movement that was founded to fight the Israeli occupation.
Its stated goal is to strike only Israeli targets, and there is no evidence that it has ever conducted military operations outside of Israel and the Palestinian territories.
It is a political and social movement as well as a military one, rooted in a community that it serves.
Although Israel alleges there are connections between Hamas and al-Qaeda, the evidence is scant and officially there is a clear distinction - Hamas condemned the September 11 attacks.
It has had semi-official contacts with Europe and America, although both the EU and the US have now branded it a terrorist organisation for killing civilians in suicide bombings.
Creating new ties?
But the assassination of Yassin may make the connections more likely.
It could inspire al-Qaeda-linked groups to carry out attacks in other parts of the world in his name.
It could also strengthen ties among regional movements that increasingly see Israel and its ally, the US, as the common enemy.
Already some Hamas officials have said the sheikh's death is part of a war against Islam, and suggested all Muslims should join in the retaliation.
For the first time, Hamas has also blamed America for the attack, saying Israel would not have acted without US approval.
And a statement purporting to come from a group connected to al-Qaeda has vowed to retaliate for the assassination by attacking the US.
'New beginning for resistance'
At the regional level, the US occupation of Iraq and its apparently unswerving support for Israel have made national Islamic movements increasingly see themselves as part of the same struggle.
Already before his death, Yassin indicated there was potential for political co-ordination - although not field co-operation - between Palestinian militant groups and those in Lebanon and Iraq.
Shia clerics associated with the militant Lebanese Hezbollah movement have condemned the assassination, blaming the US and warning of a "new beginning for the resistance".
Perhaps more ominously for the US, Iraq's most powerful Shia religious leader, Ayatollah Ali al-Sistani, has added his voice of solidarity.
He has called upon "the sons of the Arab and Islamic nations to close ranks, unite and work hard for the liberation of the usurped land and restore rights".
Ayatollah Sistani has never advocated military resistance, but he has already shown that he commands enough support in Iraq to force the US-led coalition running the country to drop or revise several political transition plans.
That would be the real nightmare for the Americans: A united Islamic front, inspired not so much by al-Qaeda, but by common national struggles against occupation.