THIS IS ABOUT the children I have seen -- the children of the Sabra camp for Palestinian refugees in Beirut and the children of Damour and, of course, the Jewish children of Metulla and Kiryat Shemona, which is across the border in Israel. Children are dying in all these places.

The other day, the Israelis bombed the Sabra camp and other Palestinian installations in and around Beirut, killing about 300 persons, according to the Lebanese government. They hit places that are called camps, but they are not camps. They are neighborhoods. The Sabra camp has been in Beirut since 1948. It is old. It has taken root. What were tents are now cottages and what were huts are now homes.

In the Sabra camp, there are courtyards with wild flowers and orange trees. In the Sabra camp, there are stores and streets and schools, and when you walk into the place, you do not realize that you have entered a camp. It does not look like a camp. It looks like a neighborhood.

To bomb the Sabra camp is like bombing a neighborhood in Washington. It is like bombing Adams-Morgan. It is like bombing Harlem or Coral Gables or Westwood or any neighborhood you can think of in any city you can think of. It is not like bombing a camp with tents and where everything is military. It is like bombing the street where you live.

It means killing children. It means killing old people and women and men and widows and shopkeepers and killing them all because they happen to live in a Palestinian neighborhood. Some may not even be Palestinians. Lebanese live in the camps. No matter. When the bombs fall, they too must die.

When I was in the camp, there were kids everywhere. They followed me wherever I went. They do not see many light-skinned, fair-haired people. there are lots of kids -- lots of kids and lots of women but not too many men. Some of the men work elsewhere in Beirut, and some work elsewhere in the Middle East and some, of course, are in the South, either attempting to kill Israelis or learning how to kill Israelis.

Only a fool could fail to understand why the Israelis took action. Only a fool does not know that the PLO also kills children -- sometimes only children. Only a fool could fail to remember the attacks on the nurseries, the children's houses at the kibbutzes where the kids all sleep together. In the Middle East, grown men kill babies and call themselves Freedom Fighters.

Only a fool could fail to understand what it is like to live up on the northern border of Israel. The artillery can come down any minute. The rockets can be deadly. The other day, three persons were killed. At night, you can hear the Palestinians and the Lebanese militia exchange artillery fire. It is like thunder in the distance. In the children's houses, baby sitters sit with weapons cradled in their arms.

Still, there is a scale to these things -- a proportion. To fire a Katyusha rocket at a border settlement is an act of war. To kill an innocent child is an outrage. But to use the most complex airplanes known to man to bomb a city neighborhood is not even in the same ballpark. What is supposed to be the proper ratio here, 300 to 3? This is what happens when a sovereign state adopts the terrorists morality of its enemies and when its leaders become captive of their own, awful personal experiences.

But the Reagan administration is not the captive of these experiences. It has to take the larger view. So far, though, its response to the bombings and the earlier raids has been timid. It admonishes Israel in a very mild way, postpones delivery of the planes that make such raids possible and then postpones delivery again. What is missing is a sense of outrage and shock that American planes are being used to kill innocent civilians in the neighborhoods of Beirut.

No one would suggest that America reconsider its friendship with Israel. This is basic and rooted in moral and democratic values that the two countries share -- not to mention strategic concerns. For these reasons, the administration seems reluctant to deal with Israel as forcefully as it should. It thinks that the issue is friendship or alliances or the Russians, but that is no longer the case. In the latest bombing of Beirut, it is the killing of innocent civilians that is the issue. If you don't condone it for your enemies, you can't for your friends, either.