• A three-stage, 5,600-km-range solid-propelled intermediate-range ballistic missile (IRBM) capable of targeting London and virtually all of Eurasia from central Iran would have a maximum range flight time of about 24 min and a boost time about 180 sec. A liquid IRBM with similar capability would have a boost burn time of about 200 sec. Either of these could be lofted or depressed at the expense of range.
• In the Middle East or northeast Asia, the defense of allies and/or U.S. forces would face shorter range threats, with total flight times of 15 min or less and typical maximum range apogees of 600 km or less. Boost times would probably be no more than 120 sec with burnout altitudes often less than 100 km. These timelines would also apply to launches from tramp steamers or submarines about 1,000 km off the coast of the United States or allied homelands. Accordingly, those threats could not be engaged in boost phase from space but might be engaged in the atmosphere during boost by forward-based platforms—either airborne or sea-based—if they were close enough.
• Based on public descriptions of the testing carried out by a potential adversary, it is likely that any threat missile launched would be part of a salvo of near-simultaneous launches of similar missiles or a variety of missile types. The salvo might be launched from sites a few kilometers apart and/or widely separated. Missiles of different types in a salvo might have different missions such as rolling back forward-based radars and forces as well as strategic targets. Similar missiles in a salvo might also have different but complementary roles such as an electromagnetic pulse precursor or defense suppression.
• Precursor attacks in particular must be considered a possible element of any threat raid because they can be implemented by any missile after exit from the atmosphere.
At some point, countermeasures of various kinds should be expected. While these may or may not be observed in tests, a reasonable assumption would be that they will be similar to those tested elsewhere.
Confidence in U.S. defense components and their ability to function as expected under stressing conditions can only be established by end-to-end operational tests that are realistic albeit limited in scope and number and by continued use of unmodified deployed systems during the life of the deployment. Of necessity, any one of these tests is expected to be constrained by cost to one-on-one or few-on few-engagements, but it would certainly be possible to inject realistically simulated data into the surveillance, acquisition, and tracking sensor measurements and messages to stress the system’s ability to function properly while han-