I wish to take exception to Edward N. Luttwak's article "No Ground Assault" {op-ed, Jan. 19}. Mr. Luttwak advocates exclusive use of air power for the removal of Saddam Hussein's forces from Kuwait.

As keen a strategic thinker as he is, it is surprising that Mr. Luttwak has grasped so little of the importance of combined arms operations. As a retired Army general, I know that each arm of service has strengths and weaknesses, but when taken together they have a synergistic effect in which the total is greater than the sum of the parts.

If we were to follow Mr. Luttwak's advice as a general policy, there might be no end to the war. Air forces can punish an opponent, but they cannot expel his troops from positions they hold if they are prepared to absorb the punishment. It is quite clear that the Iraqi leadership attaches great importance to retaining Kuwait as a 19th province. It is idle for us to attempt to predict how much punishment is needed or how long it may take before the Hussein group changes its mind.

In a way, the Luttwak argument is like the one offered by those who opposed the establishment of a date for authorization of the use of force. Had the U.N. and President Bush resolved to adhere exclusively to economic sanctions, we might have found ourselves dug in in the sands of Saudi Arabia for months or years.

A number of senior military spokesmen have made it clear that we would like to accomplish as much as possible through the use of air power. Just as we would have preferred to have resolved the problem in the beginning through diplomacy or economic sanctions, we would prefer now to do it through the pressure of air attack.

But that is open ended. Our estimates of the damage that we are inflicting may be exaggerated (as they often are), and even if the estimates are correct, the damage may be well below Saddam Hussein's threshold of pain. We learned long ago that ground forces are essential to root out a determined foe. Depressingly, the issue arises again and again in every war as people forget the lessons of the past.

Let us hope and pray that Baghdad will crack before we must resort to ground attack. Mr. Luttwak is correct in suggesting that as the way of minimizing casualties. But in the world of reality let us remember that in warfare, as in most serious undertakings, there is seldom a free lunch. EDWARD B. ATKESON Senior Fellow, Institute of Land Warfare Association of the U.S. Army Arlington