In September 2000 President Clinton announced his decision not to start deploying the national missile defense (NMD) system his Administration then had under development.  In effect, Clinton deferred the deployment decision to the next president.  As a presidential candidate, George W. Bush made clear both his belief that the Clinton system was too small and his intention, if elected, to proceed with a larger and more effective system.  After his election, President Bush soon withdrew the United States from the Anti-Ballistic Missile (ABM) Treaty and began deployment of what is now known as the Ground-Based Midcourse (GMD) national missile defense system.

After ten years of deployment (the U.S. withdrawal from the ABM Treaty went into effect on June 13, 2002) it is interesting and informative to ask how the current GMD system compares with the NMD system plan developed during the Clinton Administration.  In almost all important respects (number of interceptors, radar capabilities), the current GMD national defense system fall far short of what the Clinton plan called for.

The table below summarizes the systems.  More detailed descriptions and an element-by-element comparison follows.

Table 1.  Comparison of the current GMD national missile defense system with the initial (C-1) and final (C-3) phases of President Clinton’s proposed NMD system.

Background on the Clinton 3 + 3 NMD Plan

When the Republicans took control of both houses of Congress in 1995, they immediately began pressuring President Clinton to deploy an NMD system.  In 1996, Clinton responded by announcing the creation of the so-called “3 + 3” NMD program. Under this plan, no decision to deploy would be made immediately but development of the components of a NMD system would continue for the next three years, until about 1999-2000.  At that time, if a decision to deploy was made, the first phase of the NMD system could then be deployed in the next three years, that is, by about 2003.  Two additional phases would have then brought the system to completion by about 2010-2011.  For a detailed description of the 3 + 3 NMD plan, see the Countermeasures report.[1]

What Would the Clinton NMD System Have Looked Like?

If Clinton had decided to proceed  with deployment of an NMD system, what would this system have looked like?  The description below is of the Clinton Adminstration’s NMD system plan as of Clinton’s September 2000 announcement.  That plan called for a system that would be deployed in three phases.  If a decision to deploy was made in 2000, the initial C-1 system could have been deployed by 2005 (although it was acknowledged that 2007 was more realistic), followed by the C-2 phase, with the complete C-3 system deployed by about 2010-2011 (although this timetable was unlikely to be realized).

The C-1 system

By 2000, the projected full deployment date for the first phase of this system, the so-called Capability-1 or C-1 system, had slipped to about 2005-2007.  This C-1 system was described as being intended to counter a threat consisting of a “few, simple” warheads.

The C-1 system would have deployed first 20, and then by about 2007, a total of 100 Ground-Based Interceptors in (GBIs) silos in Alaska.  Each GBI would have been armed with an infrared homing Exo-Atmospheric Kill (EKV) that would have attempted to destroy its warhead target in a direct, high-speed collision.

The five existing U.S. Early Warning Radars (Cape Cod, Massachusetts; Beale Air Force Base in California; Clear, Alaska; Thule, Greenland; and Fylingdales, Great Britain) would receive relatively minor upgrades that would allow then to track targets accurately enough to be used to guide the GBI interceptors towards targets.  The upgraded radars would be referred to as Upgraded Early Warning Radars (UEWRs).

However, because these early warning radars have essentially no capability to discriminate warhead from decoys and other objects, an essential part of the Clinton NMD system were large X-Band Ground-Based Radars (GBRs).   These were very large and capable radars, mounted on rotatable platforms to compensate for their relatively limited electronic-scan field of view.  The C-1 system would have deployed a single GBR at Shemya Island at the western end of the Aleutian Island chain, reflecting the C-1 system’s emphasis on North Korea.

The C-1 system would have incorporated existing DSP early warning satellites (and subsequent SBIRS-High early warning satellites), and been supported by several command and control and communications facilities.   

The C-2 System

The C-2 system was an intermediate phase intended to provide a defense against a “few, complex” warheads. 

The C-2 system would have significantly increased the sensor infrastructure of the system by deploying three additional large X-band GBR radars at the Upgraded Early Warning Radar sites in Alaska, Greenland and Great Britain, and by deploying the SBIRS-Low space-based tracking system.  At that time, SBIRS-Low (subsequently the Space Tracking and Surveillance System (STSS) and the Precision Tracking Space System (PTSS)) was expected to consist of about 24-30 satellites in low earth orbits, and was to be capable of accurately tracking missiles and their warheads  through their entire flight on a global basis.

The C-3 System

The complete (objective) C-3 NMD system was intended to defend against attacks by “many, complex” warheads and was to have been completed by about 2010-2011, although it seems highly unlikely this timetable actually could have been met.

The C-3 system would have increased the total deployment of GBI interceptor missiles to 250.  Half of these would have been deployed at the C-1 interceptor site in Alaska, the other half would have been deployed in the central U.S., most likely in North Dakota. 

The C-3 system would have deployed at least four additional large X-Band GBR radars, alongside the Upgraded Early Warning Radars in California and Cape Cod, in Hawaii, and near the second interceptor site in North Dakota.  The system might have also deployed a sixth Upgraded Early Warning Radar and a ninth GBR X-band radar in South Korea.

The Current GMD System

The central missile defense objective of George W. Bush’s first term was to have an operational NMD system in place by the end of 2004, and this objective was accomplished when the Ground-Based Midcourse (GMD) System achieved a limited operational capability sometime in second half of 2004.  This rapid deployment was only possible by using the same components (interceptors, radars) that the Clinton system would have used.  Moreover, the rush to achieve an operational capability by 2004 appears to be the primary cause of some of the GMD system’s current serious problems.  At the end of 2004, the GMD consisted of about 8 deployed GBI interceptors, one Upgraded Early Warning Radar in California, the Cobra Dane radar on Shemya Island in the western Aleutians (an already existing radar that had been built to monitor Soviet missile flight tests), and associated command and communications facilities.[2]

During President Bush’s second term, the GMD system added the Sea-based X-Band (SBX) radar, the Upgraded Early Warning Radar at Fylingdales in Britain, a forward-based AN/TPY-2 X-band radar  in Japan, and a number of U.S. Navy ships received upgrades that allowed information from their radars to be used by the GMD system.  As of the end of 2008, the number of deployed GBI interceptors had increased to about 24, and plans called for a total of 44 to be deployed by 2011. 

In addition, in 2006 the U.S. announced plans to deploy 10 GBIs (these were two-stage versions of the three-stage GBIs in Alaska and California) in Poland and move a large X-Band radar from the ballistic missile defense test facility on Kwajalein Atoll in the Pacific to the Czech Republic. Although in Europe, these new facilities were intended to defend U.S. territory against possible future Iranian intercontinental ballistic missiles.

Under President Obama, these European deployment plans were cancelled and replaced by the European Phased Adaptive Approach, which aimed at initially providing a defense of Europe, with some capability to defend U.S. territory being deployed starting in 2020 or later.  During the Obama Administration, the GMD system added the Upgraded Early Warning Radar in Thule, Greenland, a second forward-deployed TPY-2 radar was deployed  in Turkey, and additional U.S. Navy ships were upgraded to have a missile defense capability.[3] On the other hand, the Obama Administration capped the GBI deployment at 30 (instead of 44) citing a lesser-than-anticipated threat, and in 2012 announced plans to place the SBX radar in a “limited test and operations” status starting in FY 2013.

Figure 1: President Clinton’s proposed C-3 National Missile Defense System.  (Figure from the Countermeasures Report)

So How Does the Current GMD System Compare to the Clinton NMD System?

In many respects the current GMD system resembles Clinton’s proposed C-1 system, although with many fewer interceptors.  However, as described below, compared to the C-2 and C-3 systems, the GMD system falls far short, both in numbers of interceptors and even more importantly in sensor capability.  Nor do there appear to be plans in place that would significantly change this situation.

Interceptors: 

The Clinton Plan: The C-1 system would have deployed 100 Ground-based Interceptors by 2007 and the C-3 system would have deployed 250 GBIs at two sites.

The GMD System: Today the GMD system deploys 30 GBIs, 26 in Alaska and 4 in California.  However, no more than 20 of these are currently considered to be operational.[4]   There are no official plans to deploy more GBIs, although some in Congress have called for the deployment of additional GBIs on at a new site on the east coast.

Upgraded Early Warning Radars:

The Clinton Plan: All five of the existing Early Warning Radars would have been upgraded and incorporated into the NMD system by 2005-2007.

The GMD System: As of today, only three of the five radars have been upgraded and incorporated into the GMD.  The MDA hopes to upgrade the radar in Clear Alaska by 2016 and the one at Cape Cod by 2017.  We’ll see.

The GMD system also added the Cobra Dane radar on Shemya Island in the western Aleutians.  This radar is in many respects similar to, but more capable than, the Upgraded Early Warning Radars.  Unfortunately, the radar is not well located and oriented for GMD use and has never even participated in a GMD intercept test.

Large X-band Radars (GBRs)

The Clinton Plan:One GBR would have been deployed in 2005-2007 as part of the C-1 system, the C-2 system would have increased this to four GBRs, and the C-3 system to at least eight GBRs.

The GMD System: Only one large X-band radar, the Sea-based X-band (SBX) Radar, was ever built and incorporated into the GMD.[5]  The SBX is somewhat smaller than the GBRs planned for the Clinton system and was built as a test asset, and thus lacks some features that would be found in an operational radar, such hardening against electromagnetic pulse effects.  No other large X-band radars are currently planned.  In the near future, the GMD will actually be going backwards in this area, since starting in FY 2013, the SBX’s budget is to be cut by more than 90% and the radar relegated to a “limited test and operations” status.

Space-based Tracking Systems

The Clinton Plan: A constellation of roughly 24 Space-Based Infrared – Low Earth Orbit (SBIRS-Low) satellites would have been deployed as part of the C-2 system.  As of 2000, official plans called for deployment of SBIRS-Low to begin in 2006, although this date would have almost certainly have slipped by at least a few years.

The GMD System:No operational space-based tracking capability is deployed.  Two “demonstration” Space Tracking and Surveillance Systems (STSS, the successor system to SBIRS-Low) satellites were launched in 2009 for test and evaluation purposes, but no additional STSS satellites are planned.  Current plans call for the deployment of two PTSS (Precision Tracking Space System — the successor system to STSS) demonstration satellites in 2017 to be followed by deployment of an operational system beginning the next year.  However, PTSS has recently come under increasing criticism and it far from clear that the program will survive.

Forward-Based Sensors

The Clinton Plan: Except for the possible deployment of an Upgraded Early Warning Radar and/or a GBR in South Korea, the Clinton Plan did not formally include any forward deployed sensors.   In part, this because such sensors would have violated the ABM Treaty (as would deploying the even the first phase of the NMD system).  However, the same sensors now forward deployed under the GMD system were then under development as the radars for the Theater High Altitude Area Defense (THAAD) and the Navy Theater-Wide theater missile defense systems.

The GMD System:Two TPY-2 X-band radars, in Japan and Turkey have been incorporated into the GMD.  In addition, a large number (currently about 23) of Navy Aegis cruisers and destroyers have been upgraded to allow them to be used for ballistic missile defense, and in particular to be able to relay their radar data back to the GMD system.  However, both of these types of radars are several orders of magnitude smaller than the GBRs would have been (in terms of the signal-to-noise they could obtain against given target at a given range) and essentially are limited to reporting back to the GMD system information about the early part of flight of an attacking ICBM (if they happen to be close enough to the launch site) for subsequent use by other sensors.