of the parties under the ABM Treaty to develop and test advanced space-based ABM systems and components. To build confidence and prevent misperceptions about such testing, the United States offered a Space Testing Assurance in October 1988. It assures the Soviet Union that United States space-based ABM testing which is permitted by the ABM Treaty could not constitute a prohibited deployment of defences. The United States pledged that only from a limited number of ABM test satellites would it conduct testing of a component of an ABM system based on other physical principles and capable of substituting for an ABM interceptor missile. Such testing would be to counter a strategic ballistic missile or its elements in flight trajectory. The number of United States ABM test satellites in orbit simultaneously will not exceed a number well short of that associated with any realistic deployed capability. To build confidence further, the United States has proposed as a predictability measure notifications for launches, tests, changes of orbits, and deorbits of ABM test satellites. The United States has also proposed that both sides be permitted to develop, test, or deploy space-based ABM radars and their substitutes without restriction. This would avoid future definitional and verification problems likely to arise because of advancing space-based technology, and it would encourage the evolution of stabilizing space-based sensors. Another major concept in the United States draft treaty is ensuring predictability in the development of the United States-Soviet strategic relationship in order to reduce the risk of nuclear war. This objective was agreed at the 1987 Washington summit. In 1988 the United States proposed predictability measures to implement this objective. These measures include annual exchanges of programmatic data, meetings of experts, briefings, visits to laboratories, and observations of tests in the field of strategic ballistic missile defence. These measures would be carried out on a voluntary, 
**Analysis**
The text appears to be discussing a treaty related to space-based defense systems and the development of advanced technologies for anti-ballistic missile (ABM) systems. The language used is technical and focused on the specifics of testing, development, and verification of these systems. The text also mentions the goal of reducing the risk of nuclear war, which suggests a focus on international relations and security.

**Category**
Science and technology, International relations