<P> EW contributes to the success of information operations (IO) by using offensive and defensive tactics and techniques in a variety of combinations to shape, disrupt, and exploit adversarial use of the EM spectrum while protecting friendly freedom of action in that spectrum . Expanding reliance on the EM spectrum increases both the potential and the challenges of EW in information operations . All of the core, supporting, and related information operations capabilities either directly use EW or indirectly benefit from EW . </P> <P> The principal EW activities have been developed over time to exploit the opportunities and vulnerabilities that are inherent in the physics of EM energy . Activities used in EW include: electro - optical, infrared and radio frequency countermeasures; EM compatibility and deception; communications jamming, radar jamming and anti-jamming; electronic masking, probing, reconnaissance, and intelligence; electronics security; EW reprogramming; emission control; spectrum management; and wartime reserve modes . </P> <P> Electronic warfare includes three major subdivisions: electronic attack (EA), electronic protection (EP), and electronic warfare support (ES). </P> <P> Electronic attack (EA) (previously known as Electronic Counter Measures (ECM)) involves the use of EM energy, directed energy, or anti-radiation weapons to attack personnel, facilities, or equipment with the intent of degrading, neutralizing, or destroying enemy combat capability including human life . In the case of EM energy, this action is referred to as jamming and can be performed on communications systems (see Radio jamming) or radar systems (see Radar jamming and deception). </P>

What are the three division of electronic warfare