It's not easy to love the MX. The House defeated the amendments proposed last week to kill the program and to delay it and study it some more. But it is clear that many members felt they faced a true dilemma. It's a legitimate feeling. There is no single happy solution to the various strategic and arms control problems we now face, and anyone trying to decide what he thinks about MX is thus faced with honestly divided counsel.

In part, the dilemma stems from previous delays. While the Soviets have been steadily deploying for the last decade the weapons that make our silo-based Minuteman ICBMs more vulnerable, we have been fiddling around in our standard fashion -- holding hearings, doing studies, haggling with one another and deploying environmental impact statements instead.

The delay has split those who normally advocate having a solid margin of safety for our strategic forces -- the hawks, if you must. Since MX won't be fully deployed until the late 1980s and the vulnerability of Minuteman is upon us now, many would put MX behind "quick fixes" that might improve our strategic posture sooner -- such as digging extra silos in the Minuteman fields and beginning a shell game with existing missiles. But the Air Force and others have feared those efforts would draw funds away from the MX; at any rate, as the quick fixes have been delayed, they have become slow fixes themselves.

The size issue itself has added to the delay. The Air Force, long interested in deploying a big missile, has only rather recently got around to thinking seriously about how to base it. This has driven even many friends of the military in Congress up the wall. But it must be noted that the Air Force has not been interested in big missiles solely because of some institutional passion for gigantism. There are economies of scale in building missiles, within reason. But survivability is the main worry. This drives us to want more, but fewer, places that an enemy would have to attack to knock them out. The MX compromises these considerations: a relatively large missile (about the size of the smaller new Soviet ICBMs), movable among a number of hardened launch points.

This means deception. The administration's critics have said that, in order to reconcile the necessarily deceptive basing with a possible arms control agreement, the administration abandoned the cheaper alternative of merely digging extra silos and instead moved to the more complex system of roads and horizontal shelters -- with the missiles lying down, not standing up -- that is now before Congress. It's somewhat easier to count missiles deployed lying down.

The administration, denying that this was a central factor, responds that it opted for horizontal basing because it is more survivable: it's possible to move the missiles around more quickly, for example, if you don't have to lift them out of silos.

In any case, the administration recently changed its proposal, and slightly reduced its cost, by moving from the famous oval "race track" to a simpler, still horizontal approach. Verification of ICBM numbers under deceptive basing is a tangled issue in its own right because the Soviets don't really need any help in verifying our compliance with arms control agreements; all they need to do is read the newspapers. The argument is more that, if we have an agreement with them that permits lots of extra silos, they might build the permitted silos and then cheat and fill them with missiles.

At this point, most people usually get a headache and start looking at the oceans, were you don't need to dig holes in order to hide. The current fad in the seagoing line of theoretical weapons is the Shallow Underwater Missile System (SUM) -- big missiles, maybe MXs, on lots of small, shallow-operating, allegedly cheap submarines. Sen. Jake Garn, is a recent Armed Forces Journal, called it Simplistic Unworkable and Maladroit.

Whether it's that bad or not, it would probably at least be considerably more expensive than many of its advocates suggest. A Marine I know says: "Amateurs talk about strategy and tactics; professionals talk about logistics." Once you start calculating the logistics, manpower, base structure and communications costs for lots of tiny submarines, the large Trident submarine may well begin to look like the best strategic bargain going.

But whether it's in little or big submarines, why not forget about MX and move the whole lot to sea? There's really only one major reason. The arcane field of anti-submarine warfare is appropriately cloaked in secrecy. Suffice it to say that our submarines are likely for the foreseeable future to remain as invulnerable as weapons ever get. But that's not good enough. In the MX debate we are talking about a key part of our ability to deter nuclear war well into the 21st century. Banking on sea-based forces (with bombers) alone for that job is putting too many eggs in the ocean's basket.

Some were wont, in the days of SALT-selling, to say that only if the SALT II agreement was approved was MX survivable, because the agreement would have limited, until 1985, the number of warheads the Soviets could put on each missile and thus would have limited their ability to target all the MX shelters. That was, and is, an absolutely terrible argument. Any system that depends for its viability on Soviet compliance with an agreement -- an agreement that by its terms expires before the system is operational -- is loony. The MX has to stand on its own feet. It has to be at least as affordable, in the absence of an arms control agreement, for us to add shelters, or otherwise improve MX's survivability, as for the Soviets to add warheads.

The House has now decided that MX passes that test and can move forward. It's easy to understand why many voted aye with a gulp and a slight wince. But it was the right call.