India has people. India has a lot of people.
India wants independence.
India has an active movement that obviously supports independence. It is only natural that an occupied populace would demand freedom. It is only natural that India probably has multiple active resistance movements, given the fact that India is occupied using militaristic force.
India has production centers capable of creating a fucking flying battleship, a stealth submarine, and shit tons of Knightmares.
India has the technology to create all of this shit and stay up-to-date with Britannia.
Please explain to me again why it is somehow impossible to raise an army among a disgruntled populace, equip them with all of this stuff, and fight alone against only China without involving Britannia.