@CrazyZ @nahtanbob
The point about fuel reserves is that they have to be commercially viable. Why would the Brits have any interest in developing lignite mines literally in the middle of nowhere.
Pak is an independent country now and has requirements of fuel. So they had a need to aggressively explore fuel resources in their land. Besides, technology has improved which makes lignite viable as a source of fuel.
As far as Pak having the lowest CAD is concerned, it is not because of Thar Coal. It is simply because it has (sadly) run out of cash/credit to import. It can simply import only as much as it can export. Mathematically, its CAD will be close to zero for some time.
Regards