How do nuclear missile defense systems account for countermeasures and decoys used by incoming missiles?

Countermeasures and decoys are methods used by an attacking missile to deceive a missile defense system by making it difficult to identify the real warhead from among the decoys. In response, nuclear missile defense systems use a range of technologies to counter these threats.

One of the main ways to counter decoys is to use multiple sensors and detection systems to increase the chances of detecting the real warhead. For example, radar and infrared sensors can be used to identify the heat signatures and other characteristics of incoming objects to determine which one is the actual warhead.

Another approach to countermeasures is to use a combination of different types of missile interceptors that are designed to handle different types of threats. For instance, kinetic energy interceptors are more effective against single or small numbers of incoming missiles, while nuclear interceptors are more effective against a large number of incoming missiles.

In addition, missile defense systems can use countermeasures themselves to confuse the attacking missile's decoy system. For example, a missile defense system can deploy chaff, which is a cloud of small pieces of metal that create a radar signature that looks like a missile to the attacking missile's radar system.

Overall, missile defense systems rely on a combination of technologies and strategies to counter countermeasures and decoys. The goal is to maintain a high level of accuracy in identifying and intercepting incoming missiles, while also minimizing the risk of intercepting a decoy and wasting resources.