Why a crossing missile can be harder to intercept

A screened task group gives its defenders a familiar interception problem because incoming weapons converge on the group. Higher attack speed reduces the time available to respond, while the approach geometry remains familiar. Some weapons also change their mode of attack during the approach, for example by dropping into torpedo mode. A ship assigned to protect a much larger area can face a weapon crossing its coverage towards a different target. Detection and interception then have to occur before the weapon leaves the area the defender can reach. An interceptor may be unable to cover the necessary distance in time even though the target passes through the nominal defensive coverage.