The Future of the ICBM

July 1, 1987

Thirty years into the age of inter­continental ballistic missiles, US policymakers are grappling again with the basic question of what part ICBMs should play in fu­ture defense strategies.

The question arises from several concerns. New generations of Sovi­et missiles, more accurate and more powerful than their predecessors, are a threat to US missiles in fixed silos. Vulnerability to attack is only part of the problem, though. The Soviets have gone to great lengths in hardening their own ICBM sites, and the capability of US missiles to hold these threatening weapons in check has diminished progressively.

Three courses of action are cur­rently being pursued to redress this imbalance. Both the Air Force and the Navy are well along with pro­grams to modernize their nuclear missile forces. Meanwhile, re­search continues on defensive tech­nologies that promise to inhibit the general effectiveness of ICBMs. (See “The Emerging Lineup for SDI,” p. 40 of this issue.) The Rea­gan Administration is also attempt­ing to reach an arms-control agree­ment that would require deep reduc­tions in US and Soviet strategic missiles.

The Administration and Con­gress, however, are not fully in ac­cord on the proper mix of strategic missiles or the best basing modes for them. The degree of reliance to be placed on ICBMs is not yet set­tled. And behind it all lies uncertain­ty about budgets for defense pro­grams of any sort in the years ahead.

An Aerospace Education Foun­dation Roundtable in Washington on April 22 took measure of the sit­uation from four perspectives. Pan­elists were Sen. Albert D. Gore, Jr. (D-Tenn.), Gen. Larry D. Welch, Chief of Staff of the US Air Force, Lt. Gen. Brent Scowcroft, USAF (Ret.), Chairman of the President’s Commission on Strategic Forces, and Dr. William J. Perry, Under Sec­retary of Defense for Research and Engineering in the Carter Adminis­tration. The moderator was Dr. Ar­nold Kanter of the Rand Corp.

General Welch emphasized the importance of being able to strike promptly against hardened ICBM silos and Soviet command centers. The Air Force says that it presently has less than half the capability re­quired to hold these classes of tar­gets at risk. Others on the panel, however, saw the vulnerability of US missiles as a problem of at least equal, or perhaps greater, signifi­cance. All, however, believed that ICBMs would be needed, along with manned bombers and missile-launching submarines, in the strate­gic triad of the future.

The ICBM, Senator Gore said, has “advantages in capability in de­terring the Soviets by holding par­ticularly valuable targets at risk that the other two legs of the triad cannot match.”

The entire panel also saw advan­tages to having at least part of the ICBM fleet in a mobile configura­tion to lessen its vulnerability to at­tack. Senator Gore, particularly, has been a leading advocate of the mobile-basing concept.

The Unstable Combination

When the ICBM was introduced thirty years ago, its striking power was recognized immediately. “On the other hand,” Dr. Perry said, “even at its first deployment, this lethality was coupled with a very high degree of vulnerability. The first ICBMs were deployed on bare pads, and therefore they were high­ly susceptible . . . to attack.”

The Air Force solved this prob­lem in the 1960s with Minuteman, using advanced propulsion and guidance technology to package the missile for basing in silos, where it was protected from attack. This so­lution lasted for about two decades. Then, Dr. Perry said, technology overtook it from various directions. Improved guidance systems in­creased the accuracy of ICBM at­tack by a factor of between three and five. Greater destructive yield became possible with smaller war­heads, a number of which could be carried on a single missile as multi­ple independently targetable reen­try vehicles (MIRVs).

Taken together, these develop­ments made the ICBM a formidable counterforce weapon that could be used to attack other ICBMs. “This combination of very great lethality and very great vulnerability to at­tack was extremely unstable and dangerous,” Dr. Perry said, citing that as “the present dilemma we face.”

In its comprehensive 1983 study of strategic modernization, the Scowcroft Commission concluded that it is not feasible today to dupli­cate the success of Minuteman, which provided survivability and maximum striking power in the same system. Instead, the Commis­sion said, the ICBM mission should be divided into two parts.

“We recommended deployment of a limited number of MX missiles in Minuteman silos to rectify the hard-target kill imbalance,” Gener­al Scowcroft said. The Commission thought this was necessary “to con­vince the Soviets that their major systems, the things that concerned us most—like the SS-18—were wasting assets and, therefore, they ought to engage in arms-control agreements with us. The MX de­ployment did nothing about the sur­vivability aspect of the ICBM force, however.

“For the longer term, we recom­mended the development and de­ployment of a small single-warhead missile. While we looked at a mo­bile-basing mode as the most likely near-term objective, we thought that the smaller the missile was, the more options one would have in the future for basing it. The single war­head [would make the small missile] an unremunerative target to attack, even if it could be located.”

Along the way, these two systems took on political colorations, with the Administration seen as favoring Peacekeeper and Congress more in­clined toward the Small ICBM (SICBM), or “Midgetman.” oppo­nents of MX claim that its ten war­heads make it a provocative and de­stabilizing weapon, one that the Soviets would be tempted to go alter early in a crisis and one the US might feel pressured to employ be­fore the Soviets could attack it. Congress has threatened several times to stop the MX program at a partial deployment and still has not approved the full complement of 100 missiles.

Critics of Midgetman, on the other hand, say the small missile is inefficient and unnecessary. Why, they ask, build 500 launchers to field 500 warheads when fifty Peace­keepers could carry the same pay­load? Sniping continues from both sides, but the President’s current program appears to have estab­lished a base for consensus.

General Welch said there is no reason—either financial or tech­nical—to force a showdown of choice between the missiles. MX deployments have already begun. And, he said, “we fully funded the Small ICBM in the Air Force budget within the three-percent guidelines [the level of requested growth, after inflation, for defense in the Presi­dent’s FY ’88 budget]. We did that at the expense of a lot of other pro­grams that are very high priority.”

Triad Within a Triad

The strategic missile moderniza­tion program is proceeding along the lines envisioned by the Scowcroft Commission. The lead system is Peacekeeper. To begin fill­ing the hard-target-capability gap as soon as possible, the first fifty mis­siles will be deployed in Minuteman silos. The Air Force achieved initial operational capability last Decem­ber with ten missiles on alert at Francis E. Warren AFB, Wyo. It proposes to deploy another fifty Peacekeepers in a “rail-garrison” mode. Twenty-five trains, each car­rying two missiles, would remain in secure air base garrisons for normal peacetime operations. In times of national need, the trains would dis­perse on railroad tracks.

The single-warhead Small ICBM is in full-scale development. It will weigh 37,000 pounds, which is con­siderably heavier than prescribed in early designs. The plan is to base the small missile initially in hard, mobile launchers at existing Min­uteman facilities, from which it could disperse rapidly in a crisis. The Air Force figures that this force mix—the Small ICBM and MX in two basing modes—is, in effect, a “triad within a triad.”

Moreover, a modernized SLBM force will complement the land-based ICBM leg of the triad. The Navy conducted the first test firing of its Trident!! (D-5) missile in Janu­ary. The D-5 has better accuracy and a larger payload than present submarine-launched missiles and is billed as “effective against most of the hardened military targets, in­cluding missile silos and launch con­trol centers.”

ICBMs and Arms Control

At the Reykjavik summit last year, President Reagan proposed that the United States and the Sovi­et Union make “deep cuts” in stra­tegic weapons. Dr. Kanter asked General Welch how the sublimits of such an agreement might affect stra­tegic modernization plans.

“The JCS [Joint Chiefs of Staff] certification as to the adequacy of the deep reduction assumed exactly the modernization program we’ve been discussing,” General Welch said. “It assumes the 1,500 modern­ized ICBM warheads—that is, 1,000 Peacekeeper and 500 Small ICBM warheads. It assumes the Trident submarines with the D-5 missiles. All of those numbers fit within the deep reduction numbers, so there is no basic restructuring of the mod­ernization program required to co­incide with the arms-control regime that we’re contemplating.”

Dr. Perry said that as moderniza­tion proceeds, especially if the stra­tegic forces are to be brought down in size, “the principal criterion we should have for deciding how to re­structure the force is one of empha­sizing survivability.”

General Welch agreed that sur­vivability is important, but said that capability is even more so. “The es­sence of deterrence is to be able to hold at risk those things the Soviets must have to succeed in an attack, and that’s done with capability.”

“I don’t think we ought to set ca­pability and survivability so far apart,” General Scowcroft said. “Capability goes to deterring the Soviets from the kind of risk-taking in crisis that they might otherwise be tempted to engage in. The sur­vivability aspect deters them from any notion of surprise attack, which could give them a significant mili­tary advantage. So I think [capa­bility and survivability] go to differ­ent points, and they’re both very necessary.”

The US has not revised the part of its arms-negotiation position that calls for a ban on mobile ICBMs. It took this stance some years ago when the Soviet Union had a mo­nopoly on mobile systems. Now, with the SICBM intended for mo­bile deployment and the Soviets even farther along on their mobile missiles, General Welch said the proposed ban has become “an abso­lute nonissue” in any practical sense.

General Scowcroft agreed that the proposal is a dead issue except on Capitol Hill, where it “leads to deep suspicion about the sincerity of the Administration’s belief in the small missile.” SICBM supporters warn that an attempt to dump Midg­etman could lead to a complete col­lapse of support in Congress for ICBM modernization.

Senator Gore said that clinging to the proposed ban on mobile missiles is “a mistake.” Even if it has some tactical value in extracting informa­tion or concessions from the Sovi­ets, “the clock is running out on the Reagan Administration so far as the START talks are concerned.”

Senator Gore explained that a sig­nificant transition in strategic policy has begun, leading “toward a future relationship [between the super­powers that] would be characterized by mutual invulnerability to a first strike. One of the ways to get that outcome is for both sides to have mobile forces that can be counted for purposes of verification [but that are] extremely difficult for the other side to target on a time-urgent basis.”

Trends in the Triad

General Scowcroft said that a fun­damental feature his Commission sought in the ICBM was “a different failure mode from any of the other legs of the triad.” The weakness of the bomber force, he said, is that it is subject to surprise attack, so that is kind of vulnerability to be avoid­ed with missile forces. He acknowl­edged the remoteness of danger from a “bolt out of the blue” sur­prise attack, but added that “you can make it either more or less re­mote, depending on what your prep­arations are.”

Technology and time have af­fected not only the ICBM but also the bomber and submarine legs of the strategic triad, Dr. Perry said. The most significant development with the manned bomber, in Dr. Per­ry’s opinion, has been low-observ­able, or “stealth,” technology. His judgment is that the bomber, “particularly when coupled with cruise missiles, is able to penetrate air defenses with a high degree of confidence. The vulnerability of the bomber is limited pretty much to the vulnerability at its base.”

He cited two technological trends working against each other on vul­nerability of missile-launching sub­marines. Today’s submarines run quieter—which would make them more difficult to detect, except for “dramatic improvements” in sonic-detection systems. On balance, he said, improvements in detection outweigh gains in quietness, and the “unfavorable trend” of the past de­cade has been toward greater vulnerability of the submarine force.

Within the mobile ICBM portion of the triad, Dr. Kanter observed, there are significant differences in response time. The small missile will need only fifteen minutes warn­ing, while rail-garrison Peacekeeper would take about three hours to dis­perse, he said. General Welch point­ed out that, of all the preparatory steps possible in response to a crisis, “the least provocative is put­ting Peacekeeper on the rails.” This could be done on the softest of warning indications.

Senator Gore disagreed, saying that rolling out the missiles would change the equation of power and confront the Soviet Union with a limited window of time to strike without losing advantage. A single-warhead mobile missile could be ready with less warning and without the risk of destabilizing the crisis, he said.

General Scowcroft acknowledged the possibility of exacerbating the crisis, but said that “one of the frus­trating aspects of our ICBM force has been that you can’t demonstrate resolve. You put them on alert, and nobody sees anything.” He pointed out that bombers can be launched as a cautionary signal to a potential en­emy and that mobile ICBMs, used properly, could achieve the same re­sult.

Elimination of any element of the triad—the ICBM, the missile-launching submarine, or the manned bomber—would make at­tack planning much easier for the Soviet Union and allow the Soviets to concentrate their defenses, Gen­eral Welch said. The historic ra­tionale for the strategic triad is that each family of systems compensates for the limitations and weaknesses of the other two.

The special advantages of the ICBM are high alert rates, relatively low cost, and rapid strike against the most difficult targets. The hard-target aspect of this capability needs improvement, but General Welch noted that “ICBMs have the full respect of the Soviets. Some seventy-five percent of their war­heads are found on ICBMs.” The combination of Peacekeeper and the small missile, he said, is “well har­monized to capitalize on the strengths of ICBMs.”