Some of my best friends support the MX. One of them, Rep. Dan Glickman, just had an article in The Post ("Why I Switched on the MX," op-ed, May 18). He sees the missile as the route to arms control, through a deal he's made with the Reagan administration. I don't think its a good deal for arms control.

The "deal" trades a very explicit missile for some very vague promises. President Reagan gets a go-ahead on MX testing and production. That's real. My friends get a letter making nebulous statements of intent to do something about arms control. What's this letter worth?

Defense Secretary Caspar Weinberger gave the game away when he volunteered on national television that the letter commits the president to "nothing basically new."

Glickman doesn't think putting MX in existing silos is a good idea. Very few people do. The silos are vulnerable to Soviet attack; the U.S. Air Force tells us. So any missile we put in them won't be available for retaliation. It will be available for a first strike, but of what use is that if, as Reagan says, first strike isn't U.S. policy?

If we can't use MX after a Soviet attack and we won't use it before a Soviet attack, we are left with a militarily missionless missile. Conceding this, MX supporters shift the argument to arms control.

MX is a dumb idea, my friend Dan and other MX supporters say, but we need it anyway, to support the smart idea of arms control. Publicly, the argument is that we need MX to get the Russians to the bargaining table. MX will be particularly effective at this, Glickman tells us, because the Russians fear ICBMs most, as demonstrated by the fact that this is where they've put the bulk of their strategic effort; this is the kind of weapon they understand.

The idea that the Soviets find the familiar more threatening than the unfamiliar is dubious psychology, and, in my experience, flat-out wrong. As a congressional adviser to the SALT II delegation, I had extensive discussion of strategic issues with middle- and high-level Soviet officials. Invariably, I found their latest concern to center on those U.S. weapons which were different from and far in advance of theirs: anti- submarine warfare, small-radar-image aircraft and, most of all, accurate cruise missiles. I heard not one word of concern about MX, which at that time under the Carter racetrack scheme was a far more viable weapon than that which we are debating today.

Privately, Scowcroft Commission members and congressional MX advocates concede that the arms control problem lies less with the Soviets than with the White House. But it leads to MX nevertheless, they tell us: we've made a deal; we give Reagan the MX and he'll convert to sincere arms control.

It can't be done. You can lead a horse to a steeplechase but you can't make him win it. Negotiating weapons with the Soviets is difficult and arduous. It requires both high competence and burning dedication to arms control as a national security tool. This administration has neither. It is convinced in its bones that real men don't control weapons, they build them.

The new arms control promises Reagan now makes to gain MX support are reminiscent of the old promises to "sit down with the Soviets and hammer out an agreement" he made in 1980 to gain election. His delivery of the 1980 deal consisted of (1) refusing to ratify SALT II, (2) abandoning Comprehensive Test Ban negotiations, which had been supported by three Democratic and two previous Republican presidents, just as they approached fruition, (3) turning all key arms control positions over to prominent opponents of arms control, with the most dogmatic of these being given the greater power, and (4) concocting negotiating positions designed to score propaganda points rather than reach agreement. These policies and people remain, my friend Dan's New Deal notwithstanding.

If the president doesn't produce on arms control, Dan tells us, we'll kill the MX later. Don't count on it. With each passing month, the number of people employed on the program will increase, and with it the political penalty legislators will face when they consider canceling it. With each passing billion dollars, the dismal argument that "we've come too far to turn back" will gain more adherents.

Good arms control proposals abound. SALT II ratification is ours for the asking. A comprehsive test ban treaty, as I suggest, could be concluded without long delay. The nuclear freeze would improve deterrence imensely, by denying both sides the reliability needed for first strike. If we want these good ideas, we must pursue them directly. You don't get to a good idea by going through a bad idea. The best thing to do with a bad idea is to kill it and the best time to do that is at once.