Final_Review - IR 381: Final Exam Review IMPORTANT TERMS...

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IR 381: Final Exam Review IMPORTANT TERMS Boost, Midcourse, and Terminal Phases Boost phase: The portion of the flight of a ballistic missile or space vehicle during which the booster and sustainer engines operate until it reaches peak velocity. This phase can take 3 to 4 minutes (for a solid rocket shorter than for a liquid-propellant rocket), the altitude at the end of this phase is 150-200 km, and the typical burn-out speed is 7 km/s. Boost-phase intercept is a type of missile defense technology that would be designed to disable enemy missiles while they are still in the boost phase. Mid-course phase: The midcourse phase of a flight is when the middle part of the trajectory is traversed. In particular, the midcourse phase of the flight of an ICBM is the longest phase, outside the atmosphere and without propulsion. The midcourse phase of a ballistic missile trajectory allows the longest window of opportunity to intercept an incoming missile up to 20 minutes. This is the point where the missile has stopped thrusting so it follows a more predictable glide path. The midcourse interceptor and a variety of radars and other sensors have a longer time to track and engage the target compared to boost and terminal interceptors. Also, more than one interceptor could be launched to ensure a successful hit. A downside to the longer intercept window is the attacker has an opportunity to deploy countermeasures against a defensive system. However, the interceptor and other sensors have more time to observe and discriminate countermeasures from the warhead. Terminal Phase: A missile enters the terminal phase when the warhead falls back into the atmosphere. This phase generally lasts from 30 seconds to one minute. Calculated Ambiguity: The means of retaliation to an attack are intentionally left ambiguous by a defender. The policy is intended to strengthen the ability of the US to deter a chemical or biological attack, by leaving open the possibility that the US will respond to such an attack with a nuclear strike. This was the cornerstone of Eisenhower’s massive retaliation. Scott Sagan argues that this policy may give rise to a commitment trap, where ‘the US would feel compelled to retaliate with nuclear weapons in order to maintain its international and domestic reputation’, that is, to maintain credibility. For example: Eisenhower’s Massive Retaliation policy. Counterforce Targeting: A type of attack originally proposed during the Cold War, it refers to the military strategy of targeting elements of the military infrastructure, usually either specific weapons or the bases which support them. This strategy attacks these targets whilst leaving the civilian infrastructure (countervalue targets) as undamaged as possible. However, many military targets are located in proximity to civilian centers. Counterforce targeting also undermines nuclear deterrence, in that both sides are more likely to believe in the possibility of a first strike attack, possibly preempting conflict. A counterforce exchange was one scenario mooted for a possible limited nuclear war:
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This note was uploaded on 03/25/2008 for the course IR 381 taught by Professor Manning during the Spring '07 term at USC.

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Final_Review - IR 381: Final Exam Review IMPORTANT TERMS...

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