Although this isn't something that will have direct effect in our games and the world, it's a very present thing in the minds of the citizens of the British Empire. Not unlike sudden discussions of Iraq, North Korea or Iran popping up in our present world.
The British Empire is fighting proxy wars in several areas of the world. Unlike twenty years ago when these were full blown hot wars, they are now not quite cold wars, but are being fought by proxy in several areas of the world.
The two primary adversaries are the Ottoman Turks and the Chinese. They both threaten India, the Ottoman's in the West and the Chinese in the East. The Ottomans have been held to Afghanistan by the British proper and Afghan tribesmen being supplied by the British. Not unlike the current wars the US is fighting in the mountainous areas of Afghanistan, the Ottoman advance into India has been held in these same brutal passes. This is one of the most challenging fronts in the entire British Empire with the lines shifting dozens of miles literally overnight.
In the East, the Chinese have been held at the Irrawaddy Delta. Backing the Kingdom of Siam and supplying troops from Burma, the British have been fighting the Chinese to a standstill through the Siamese. A treaty of mutual protection has served both well to halt Chinese aggression in SE asia as it pushes west. Attempts by the Chinese to make military forays across the Himalayas have been stopped with heavy casualties in manpower and equipment. The Chinese have largely abandoned attempts to fight their way across the mountains in the last decade.
There are some notable things which have solidified the Chinese and Ottoman Empires as the primary enemies of the British Empire. While territorial interests are part of this, despotism and inhumanity are some of the things that underpin the Empire's battle with these governments.
The Ottoman's use of "War Ghuls" is one of the most despicable acts in the history of warfare. The use of these Ghuls is the reason why the Afghan tribesmen are strongly allied with the British. The first report of these terror troops being used was after the Afghans had pushed the Turks out of tribal areas. During this time, the Afghans were largely equally disposed to both the British and the Ottomans, they would trade and negotiate but at the end of the day they did not want either force in their areas. That all changed when the Ottomans deployed the War Ghuls. Afghan prisoners and civilians were intentionally exposed to the Æster and then these Æster mad men, women and children were driven down onto other Afghan villages. The ensuing chaos was predictable. This tactic was used again and again by the Ottomans without remorse. It was this tactic that caused the Mullah's to declare Jihad against the Ottomans. This forever changed the balance of power in the region. Afghan tribes became allies of the British and the Ottomans thereafter were unable to hold territory for very long in tribal areas.
The Ottoman's have also bred the Janissaries. These soldiers grow up breathing a mixture of Æster and opiates. When in battle, the Janissaries are not Æster mad but have many of the benefits of the Æster mad; this makes them almost unstoppable. Reports of them continuing to fight with limbs hacked off and literally tearing opponents apart with their hands have made them legendary. If captured, they quickly die when their breathing media runs out. Attempts to replicate the formula they breathe have failed utterly and so no attempt is made any longer to take Janissary prisoners. To kill them outright is kinder than the slow horrific death they would suffer as a result of withdrawal from the Æster opiate concoction.
The Chinese have similarly taken to using inhumane tactics in their attempts to expand. While they do not intentionally expose their own troops to the Æster, they have been reported as marching entire villages of their own people into the mountains where Æster exposure is almost certain. The reason for these activities cannot be directly determined, but investigation points to studying the effects of Æster exposure on those people. The use of Æster warheads by the Chinese is something else that is common knowledge. These warheads have been devastating against the Siamese. International outrage has accompanied reports of the use of these warheads against troops.
The Ottoman Turks and the Chinese pose the greatest threat to the British Empire and way of life.