Other options for missile defense could include lasers deployed from drones that would destroy incoming weapons and a system that's now in place uses interceptor missiles to blow up ones that are in flight.
The Columbia president Juan Manuel Santos has criticized the ENN rebel group for blowing up two oil pipe lines in the north of the country just days before a bilateral ceasefire is due to come into force.
哥伦比亚总统桑托斯(Juan Manuel Santos)批评ENN叛军组织在双边停火协议即将生效几天之前炸毁北部两条输油管道。