Memo to self:
1. Invent new non-fossil fuel.
2. Invite the mediaeval folk existing in hot sandy places to find a new use for black smelly liquid.
3. Then realise there's no-one left to have a war with - so why do we need anything mechanical using non-fossil fuel for our Armed Forces? Sharpened guava halves will do - and big sticks with pointy ends.
4. Find out where the best guavas come from and make them an offer.....