Yes it was...
'After the Great Eastern Crisis broke out and the Russians sent an uninvited diplomatic mission to Kabul in 1878, Britain demanded that the ruler of Afghanistan, Sher Ali, accept a British diplomatic mission. The mission was turned back, and in retaliation a force of 40,000 men was sent across the border, launching the Second Anglo-Afghan War. The war's conclusion left Abdur Rahman Khan on the throne, and he agreed to let the British control Afghanistan's foreign affairs, while he consolidated his position on the throne. He managed to suppress internal rebellions with ruthless efficiency and brought much of the country under central control.
In 1884, Russian expansionism brought about another crisis – the Panjdeh Incident – when they seized the oasis of Merv. The Russians claimed all of the former ruler's territory and fought with Afghan troops over the oasis of Panjdeh. On the brink of war between the two great powers, the British decided to accept the Russian possession of territory north of the Amu Darya as a fait accompli.
Without any Afghan say in the matter, between 1885 and 1888 the Joint Anglo-Russian Boundary Commission agreed the Russians would relinquish the farthest territory captured in their advance, but retain Panjdeh. The agreement delineated a permanent northern Afghan frontier at the Amu Darya, with the loss of a large amount of territory, especially around Panjdeh.'
The Great Game - Wikipedia, the free encyclopedia
'Signed on August 31, 1907, in St. Petersburg, Russia, the Anglo-Russian Convention of 1907 brought shaky British-Russian relations to the forefront by solidifying boundaries that identified respective control in Persia, Afghanistan, and Tibet.'
Anglo-Russian Entente - Wikipedia, the free encyclopedia
'The Russians accepted that the politics of Afghanistan were solely under British control as long as the British guaranteed not to change the regime.'
The Great Game - Wikipedia, the free encyclopedia
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The Durand Line (Pashto: د ډیورنډ کرښه) refers to the 2,640 kilometers (1,640 mi) long porous border between Afghanistan and Pakistan. It was established after an 1893 agreement between Sir Mortimer Durand of British India and Afghan Amir Abdur Rahman Khan for fixing the limit of their respective spheres of influence as well as improving diplomatic relations and trade. It is named after Sir Mortimer Durand, K.C.I.E., a British diplomat and civil servant of colonial British India.
Afghanistan was considered by the British as an independent princely state at the time, although the British controlled its foreign affairs and diplomatic relations.
Durand Line - Wikipedia, the free encyclopedia
So, the northern border was determined by a British-Russian agreement without even consulting the Afghan people. While the Eastern border was decided by the British and an Afghan leader who was in Britain's back pocket.
And you say 'Afghanistan was not formed by 'colonial masters''.
Suuuuuuure it wasn't.
As for Afghanistan being a joke as one country:
'the main northern ethnic groups, Tajik, Uzbek and Hazara, who together account for about 60 percent of the population, in order to drive the Taleban from power in 2001. But the Taleban were and still are the major political vehicle for the Pashtuns, who are about 40 percent of the population.'
Gwynne Dyer: Afghanistan an unwinnable war - StumbleUpon
America is trying to train a united Afghan army and they are supporting a corrupt central government. They are DEFINITELY trying to keep Afghanistan together.
Afghanistan is a collection of tribes/ethnic groups that were pushed into the present boundaries mostly by colonial powers. The people were forced into it and were never given a say in the matter.
It is now time for the West to butt out what is none of their business and let the Afghani's decide their own fate.
You do not agree - fine.
If you want to ignore the obvious and history...go ahead.
Good day.