Like 9/11, will Hamas attack mean wider Mideast conflict?

It is being called Israel’s 9/11.

That may understate the impact of the Hamas ground invasion that last weekend swept, unimpeded, across the country’s southern border with Gaza, sowing terror. But one parallel with America’s ordeal is already clear.

The political aftershocks of the attack will reverberate far beyond the sliver of Mediterranean land where it began.

Already, Mideast heavyweights Iran and Saudi Arabia are limbering up for a new round of their strategic tug of war. Suddenly, the United States finds itself more directly engaged in the region than it has been for a decade.

And its engagement there could affect engagement elsewhere: in Ukraine, for example, which, until last Saturday morning, was top of America’s and its allies’ foreign policy agenda.

How all this plays out will depend on how, and how quickly, the immediate response to the attack by Hamas from Gaza ends. And that will depend not only on Israel’s government and military commanders, but also, first and foremost, on Iran.

For Tehran has not only been funding and equipping Hamas.

Across Israel’s northern border, in Lebanon, the Iranians have forged the Shiite Hezbollah movement into what is essentially a surrogate army, obeying Tehran’s orders.

Hezbollah dwarfs Hamas’ capabilities. It has some 150,000 missiles, far more advanced and accurate than Hamas weapons. They are capable of hitting towns and cities across Israel, as well as key infrastructure such as its international airport.

If Hezbollah enters the fray, a decision that would have to be made in Tehran, the war in Gaza would threaten to become a regional conflagration. Israel would inevitably attack Lebanon. The U.S. itself might well be drawn in militarily.

So far, Hezbollah’s missiles have remained unused, despite skirmishes across the Lebanon border.

But Washington is worried. That is why President Joe Biden has dispatched a naval carrier group to the eastern Mediterranean, and why, in a White House statement Tuesday, he had a terse message for anyone thinking of joining Hamas’ fight: “Don’t.”

His message to Israel has been, in effect, “Do.” Mr. Biden said that in Israel’s shoes, America would launch a retaliation to Hamas’ “evil” assault that would be “swift, decisive, and overwhelming.”

But, like America’s response to 9/11, that could reverberate in ways that are unpredictable and difficult to contain.

In America’s case, they included costly, painful, and ultimately unsuccessful wars in Afghanistan and Iraq stretching over decades.

For Israel, breaking Hamas’ iron hold on Gaza would mean overcoming an array of obstacles.

The Israeli army is hugely more powerful than Hamas. But what about the dozens of Israeli civilians being held hostage in Gaza? And if Israel mounts a major ground assault, how will its soldiers deal with the house-by-house fighting, ambushes, and improvised explosive devices that await them?

The political challenges could prove equally formidable.

Mr. Biden coupled his backing for Israel with a reminder of the “laws of war,” signaling the importance of doing everything possible to avoid civilian casualties. But any full-scale attack on Gaza will inevitably take the lives of many hundreds of noncombatants.

The horror of Hamas’ weekend rampage means that Israel, for now, enjoys the broad sympathy of much of the outside world. But a protracted attack on Gaza – with mounting casualties and hardship for its civilians – could sorely strain that support.

There is another open political question, also echoing America’s experience after 9/11. If Israel does remove Hamas as a military and political force in Gaza, what would take its place? Israel pulled its soldiers and settlers out of the Gaza Strip more than a decade and a half ago. The nominal Palestinian leader in the West Bank, the aging and increasingly unpopular Mahmoud Abbas, could not fill the void.

All this may help explain why Israel has not yet sent its massed troops into Gaza.

But if it does launch an invasion, the political aftershocks are likely to reverberate for far longer than the fighting.

And they will impact the balance of power in the Middle East.

Washington had been hoping to broker a peace deal between Israel and Saudi Arabia, offering formal security guarantees to the Saudis. The twin goals have been to balance growing Iranian power, and China’s expanding influence, in the region.

That deal is off for the foreseeable future. Saudi Arabia will be highly reluctant, amid Arab sympathy for the Hamas attack, to make peace with its historic enemy.

But if and when Riyadh comes back to the table, it seems likely that the Saudis will insist on something that until last weekend appeared extremely unlikely – a serious new effort to resolve Israel’s conflict with the Palestinians.

For now, the sheer horror felt by Israelis in the face of Hamas’ slaughter of civilians has left the idea of a two-state peace agreement more distant than ever.

But for Israel’s key overseas allies, the attack has underscored the impossibility of achieving long-term stability in the Middle East without a political resolution of the Israeli-Palestinian issue.

The question then will be for Israelis to answer. With their sense of security so painfully and cruelly shattered, will they too, over time, conclude that they share a mutual interest in seeking accommodation with other Palestinian leaders ready to choose peaceful coexistence?