Israel’s legal right to pursue Hezbollah into Lebanon should not be in dispute. The United States’ mission into Afghanistan five years ago provides ample precedent. But, as the United States has discovered, the practicalities – and impracticalities – of actually pacifying Muslim territory are daunting.

So prospects for a secure peace – for Israel and for the United States – depend on more than military force and international law. Most likely, peace depends upon a political agreement, specifically a brutal bargain with Arab governments.

Meanwhile, if the Lebanese government can’t or won’t keep Hezbollah under control, Israel has a right to act energetically in its own self-defense. That’s exactly what the United States did after the Sept. 11 attacks; if the Taliban government of Afghanistan wouldn’t hand over Osama bin Laden and other criminal culprits, America had a perfect right to use military force in “hot pursuit,” halfway around the world.

But then came the hard part: What should the United States do in Afghanistan after it got there? Letting bin Laden slip away counts as a major failure, but Murphy’s Law applies in wartime, too. The continuing problem has been America’s attempt to manage the lives of 28 million Afghans. At first, we were truly greeted as liberators. But that didn’t last very long; foreign occupiers are never welcome, anywhere, for a protracted period.

Of course, the Americans could carpet-bomb the entire country – which would “work,” in the sense that ethnic cleansing works. As the English speakers proved in North America from the 17th through 19th centuries, exterminating the locals is a proven technique for subduing a piece of territory. But in modern times, of course, such genocidal tactics are deemed unacceptable.

Also unacceptable, for a different reason, is the plan of administering a hostile population. The Israelis have tried, and failed, to do that in the West Bank and Gaza for the past 40 years. Indeed, the Israelis have tried to rule over parts of Lebanon before – unsuccessfully.

Back in 1982, after similar provocations across the Lebanese border, the Israeli military invaded that nation, driving all the way to Beirut. As with the United States in Afghanistan or Iraq, the initial offensive was easy, but the long-term occupation was a killer. Eventually, the Israelis had to withdraw, leaving behind hundreds of thousands of ever more angry Lebanese, operating in anarchy.

Yet, even now, the Israelis seem to have little stomach for a repeat of the 1982 invasion and occupation. As a military source told the Israeli newspaper Ha’aretz: “It is impossible to crush a popular, religious movement.” More precisely, it is impossible for the Israelis to do the crushing, since Israel, like the United States, operates under the close scrutiny of a mostly hostile world media.

So who could crush “a popular, religious movement”? The answer in Lebanon is the same as in Afghanistan and Iraq. Only fellow Muslims can do the job.

For better or worse, Arabs and Muslims are not held to the same legal standard by international law and opinion. And yet in most places in the Arab world, including Syria, would-be terrorists are kept in check by governments that know how to fight fire with fire. In other words, terrorists are best subdued by terrible governments. And the Arabs have plenty of those; the challenge is to figure out how to persuade such rough customers to take responsibility for policing Lebanon.

Not an appealing prospect? That’s for sure. And is it in contradiction to the goal of fostering democracy and human rights in the Middle East? You bet.

But truly tough tactics – that is, ruthless on-the-ground military force, applied by Arabs not fearful of international norms or international law – are the best option that Israel has for settling its Lebanon problem once and for all. And, yes, a similar toughness is the best-available solution for the United States in Afghanistan and Iraq, too.