This is a fun anime, but its explanation of the necessity of war for geopolitical growth and stabilization is scarier than cow tongue lollipops.

http://en.wikipedia.org/wiki/List_of_economic_expansions_in_the_United_States

What usually happens (as opposed to what they explained).

1) Large wars often produce unprecedented demands on industry and national workforce

2) This increased demand leads to price increases. Commodity prices can rise to over 100% Food, Healthcare, and anime

3)This often creates profiteering networks like our energy sector

4)The government will then put into effect price controls and perhaps rationing (food, healthcare, raw materials [metal for air craft carriers ] etc.).

5) Price controls can mess up your "free market" ideals and your net exports vs imports. Also Unions can become more pronounced to try to balance government and economic mandates.

6) Conscription and increased workforce demand place stress on families this psychology feeds back into the economy into paying off of debt, saving money instead of spending it etc.

7) This can mean the government gets less taxes (definitely State taxes on commodities). OR just borrows 8 days a week from China...

8) Government sometimes takes over essential industries (power, transportation, metal, energy etc). Once the war ends these can be propped up, maybe gracefully restructured (good luck), or just fall apart.

9) Not really expecting anyone to make it to point 9... but if you are reading this, I love you <3