Ok, joking aside guys....how EXACTLY can GB Plc "project" its military power?
Who's joking? But to answer your question, it involves primarily three things:
1. A military designed to be expeditionary rather than be a garrison force. In other words a military that is designed to operate from places other than their home base. This sounds simple, but is actually exceedingly difficult to achieve. Very few nations have ever developed military forces that can deploy globally. The USA and UK are the only two I can think of.
2. Overseas bases to deploy your forces to, and from which you can sustain long term operations. Basically, only the USA and UK have such bases globally and not just regionally. The USA is unique in that it has mobile bases in the form of carrier battle groups.
3. A support infrastructure able to support military forces that are globally deployed.
As for item 1 above, the UK developed that ability in the mid to late 19th century and while it has since atrophied, enough has been preserved to maintain a global presence. The US began developing that ability between the world wars and fully developed it after WW2. No other nation that I know of has even attempted it, although Japan got somewhat of a start just before WW2 but completely lost it after the war. You should read Alfred Thayer Mahan. He was mandatory reading where I went to school. And if you want to go back to antiquities, Rome sort of achieved it in the Western world. Rome's greatest weapon was (arguably) its road systems that enabled it to move large armies rapidly and sustain them in the field. And while it never got the prestige of the Roman Legions, Rome's Navy was instrumental in the Roman Empire's expansion and intrumental in sustaining it.