One reason that national defence is a classic example of a public good is that
◦ it would be immoral for private firms to provide this essential commodity.
◦ all citizens want national defence.
◦ military technology is too expensive for private firms to provide.
◦ the benefits that accrue to one person do not diminish the benefits available to others.
◦ society deems it to be too important to be provided by the private sector.