Theory must be met with practice, they mutually inform and reinforce each other. The important bit is that we cannot rely on simple empiricism and feel out better or worse policies when the entire system needs to change. This is where theory helps us understand what our systems are naturally leading towards, and what will replace them. The world will not be made better by imperialist countries trying slightly different policies gradually, but instead by the adoption of socialism and the end of imperialism and neocolonialism.