Boost-glide weapons are generally designed to avoid existing missile defense systems, either by continually maneuvering or by flying at lower altitudes to reduce warning time. This generally makes such weapons easier to intercept using defensive systems intended for lower-altitude "low-tier" targets. Flying at lower speeds than short-range ballistic missile warheads makes them easier to attack. Those that approach with very low terminal attack profiles are even subject to attack by modern hypervelocity guns and
railguns. The evasion capabilities that HGVs employ are largely limited to the upper atmospheric flight span.
