A directed-energy weapon counter measure apparatus and method for modifying a path of a focused electromagnetic energy beam (204) emitted by a directed energy weapon system so as to deflect it from a platform (200), the apparatus comprising an electromagnetic radiation source, communicably coupled to a control system. The control system is configured to create an atmospheric element (202) operative to simulate a physical electromagnetic radiation path modifying device within an atmospheric volume located in the path of the focused electromagnetic radiation beam (204) by causing electromagnetic radiation from the source to be applied to a selected plurality of three-dimensional portions of said atmospheric volume so as to heat and/or ionise the air with in said portions, wherein said selected portions are spatially located together in a substantially unbroken, three-dimensional configuration.