Destroying Enemy Productive Capacity

The sentences given in each question, when properly sequenced, form a coherent paragraph. Each sentences is labelled with a letter. Choose the most logical order of sentences from among the four given choices to construct a coherent paragraph.

1. But in the industrial era destroying the enemy’s productive capacity means bombing the factories which are located in the cities.
2. So in the agrarian era, if you need to destroy the enemy’s productive capacity, what you want to do is burn his fields, or if you’re really vicious, salt them.
3. Now in the information era, destroying the enemy’s productive capacity means destroying the information infrastructure.
4. How do you do battle with your enemy?
5. The idea is to destroy the enemy’s productive capacity, and depending upon the economic foundation, that productive capacity is different in each case.
6. With regard to defence, the purpose of the military is to defend the nation and be prepared to do battle with its enemy.