A modern window casement cannot simply be lifted out of the frame anymore. This is because casements are now typically built to be flush with the frame and are held tightly by mushroom cams. With aluclad wood windows, even attempts at breaking apart the frame itself usually fail, as the wooden profile and its light metal cover protect the frame from impact. The additional aluminum cladding strengthens an already tough and secure wooden window.
Further increases in security can be achieved with muntins for example. Even ordinary triple glazing can significantly improve the security offered by any aluclad system when muntins are included in the construction. The best possible security comes with choosing laminated safety glass or impact resistant glass.