One cannot, as an Israeli, feel anything but shame at the way one’s government has reacted to the influx of hundreds of Sudanese refugees, many of them from Darfur, who have recently crossed the border from Egypt into Israel.

Or perhaps one should say “has not reacted,” because apart from stating its intention of returning them to Egypt, Prime Minister Olmert’s government has done nothing while the penniless Sudanese whom have been rounded up by the army, whose patrols have found them on the Israeli side of the desert border between Sinai and the Negev; taken to the Negev’s main city of Beersheba; dumped unceremoniously in its streets; and left to fend for themselves with what help they have been able to get from local authorities and volunteer organizations.

It is impossible not to make the comparison with the government of Menachem Begin 30 years ago, one of whose first acts after coming to power in 1977 was to welcome to Israel a boatload of 66 Vietnamese refugees found at sea.

Of course, Begin’s decision was in a way pure theater. Sixty-six Vietnamese were hardly a burden, and in terms of the hundreds of thousands who had fled Vietnam and were looking for a new home, they were less than a drop in a bucket. Nor was Israel threatened with the arrival of more Vietnamese once a first group of them was accepted.

The South China seas were far away and their waves were not about to sweep up more boats on Israel’s shores.

This is not the situation with the Sudanese. Egypt, which has treated them badly, and in which no volunteer organizations have offered to help, has a long land border with Sudan and a much shorter but still extensive one with Israel.

Tens of thousands of Sudanese refugees, if not more, are now on Egyptian soil. A thousand of them, hearing that in Israel at least someone cares about them, have already trekked across the frontier, and the number is now growing by several hundred each month. Clearly, Israel cannot afford to let itself become the destination of unlimited numbers of them.

And this is not only because Israel is a small country with limited means. It is also because it is already a country with vexing problems regarding immigration, potential future immigrants, and foreign workers, its policies toward which could hardly be justified if it started taking in all the Sudanese who arrived.

How would one explain to the estimated 17,000 Jews still left in Ethiopia because their ancestors converted outwardly to Christianity that Sudanese with no Jewish connection at all can come to Israel and they can’t?

How would one explain it to the 7,000 Jewishly-living B’nei Menashe of northeast India, in whose face the gates of Israel have been slammed?

How would one explain it to the tens of thousands of illegal foreign laborers deported by Israel despite their being hard workers and the parents of children who never had any other home?

The line has to be drawn somewhere. But this is precisely where the difference between Begin and Mr. Olmert is so great.

Although Begin knew that Israel could not solve the Vietnamese refugee problem, he understood the importance of a gesture — and not just the public relations importance, but the deeper moral importance as well. He knew that the government of a people many of whose members had perished in the Holocaust because no place in the world had wanted Jewish refugees should stand up and make a symbolic statement.

“We can’t do much,” this statement said, “but we’ll do the little we can.” Israel could actually have done a bit more at the time, but no matter. Begin did the right thing and he did the smart thing.

What the Olmert government is doing is wrong and stupid. No, Israel cannot solve the Sudanese refugee problem, either. But it could make a symbolic statement now, too.

It could say: “A thousand Sudanese have arrived in Israel so far. Several hundred are from Darfur, where genocide has taken place. We cannot and will not turn these several hundred away. We will welcome them and help them to live here as long as they wish. The others, unfortunately, will have to be sent back to Egypt — and we will also, alas, have to turn back all Sudanese refugees in the future, even if it breaks our hearts to do so. But we do have hearts and we want the world to know it.”

The Olmert government, it would seem, prefers the world to think Israel is heartless. At a time when much of the world already does think that, and when Israel is losing a propaganda war that it cannot afford to lose, such behavior is almost criminally insensitive.

Beyond this, Israel’s Sudanese refugee problem, which already has planners talking about the need to build a fence the entire length of the Egyptian border just like the West Bank “security fence” that is now going up, demonstrates that Israel, for the foreseeable future, does need fences — and not for security only.

As a first-world country surrounded by second- and third-world neighbors, it will more and more become the destination of masses of human beings seeking refuge and work unless it has the means to keep them out. One cannot ask the Israeli army to devote itself to such a task. A physical barrier is the only thing that will work.

In this sense, the entire argument over whether the West Bank fence is or is not justified by Palestinian terror is an academic one. It would have to be built anyway, just as a Negev fence will have to be built too. It’s a cruel world. There’s just no need for any country to be crueler than it has to be, especially if it’s a Jewish one.

Mr. Halkin is a contributing editor of The New York Sun.