I was reading about the handover and how Britain had a lease on New Territories but held Hong Kong island outright, ie with no agreement to hand back after 99 years.
So, could the UK have given back New Territories but kept the island of Hong Kong and if so, why did they give it all back?
I am not a historian, however until someone more informed comes along...
The Treaty of Nanking in 1842, the Treaty of Beijing in 1860, and The Convention for the Extension of Hong Kong Territory in 1898, gave the UK the control of Hong Kong Island, Kowloon (area south of Boundary Street), and the New Territories (area north of Boundary Street and south of the Shenzhen River, and outlying islands), respectively. Although Hong Kong Island and Kowloon had been ceded to the United Kingdom in perpetuity, the control on the New Territories was a 99-year lease. The finite nature of the 99-year lease did not hinder Hong Kong's development as the New Territories were combined as a part of Hong Kong. By 1997, it was impractical to separate the three territories and only return the New Territories as Hong Kong is economically dependent on the surrounding area.
Not to mention the political and strategic military impracticalities of opposing the Chinese on their own doorstep. The Chinese could have reduced Hong Kong to a husk of it's former self if they chose to embargo it, and could have easily taken it militarily.