(PS: My apologies, everyone. Something came up yesterday and delayed me for the day. I returned to Chongqing today, so updates are resuming. There will be another one tonight, and I'll try for three updates tomorrow.)
Europa was an important human colony in the Solar System because of the unique celestial body that was Jupiter.
As the largest planet in the Solar System, Jupiter was an enormous gas giant composed mostly of hydrogen. Its unique solid hydrogen, especially metallic hydrogen, was extraordinarily valuable to human civilization. Europa was the most important hub for collecting, preliminarily processing, and transporting metallic hydrogen.
Thus, the Europa colony was no minor outer-space settlement. Unlike colonies in the asteroid belt or on Mercury, its status was equivalent to that of the lunar and Mars colonies. It was one of the Azure Government's three directly governed human colonies.
For such an important Solar System colony, Europa's colonial cities were massive, with an official population exceeding ten million. And that was merely the official figure. Add in illegal immigrants, illegal laborers, smugglers, mercenaries, people doing even dirtier work, trafficking victims... the actual population was probably as high as fifteen million.
A Solar System colony with such enormous value and a population in the tens of millions also had a permanent government force of 150,000 troops. These were not local peacekeeping units, but genuine colonial field forces capable of fighting in space. They were also supported by a Solar System fleet consisting of one space battleship, two space cruisers, six space destroyers, and more than ten gunboats.
It could be said that Europa's armed forces were already extremely formidable. Even though it was far from Earth, and gangs and criminal industries ran rampant, such military strength should have been more than enough to suppress everything with ease—barring unforeseen