Who are the key players in Afghanistan?

Updated 3:14 PM ET, Tue September 19, 2017

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(CNN)Like two US Presidents before him, Donald Trump has a plan to win the United States' longest-running war.

In a long-awaited speech this month, Trump made it clear the US will remain a major actor in Afghanistan for years to come -- doubling down on the conflict with a likely troop increase -- but he also called on other countries in South Asia to do their part.
Once a key battlefield in the "Great Game" between major world powers in the 19th century, Afghanistan today is a mess of overlapping foreign policy and security interests for regional and international powers.
Who are the key players?

United States

The US invaded Afghanistan on October 7, 2001, after the Bush administration accused the country's then Taliban government of sheltering al Qaeda leader Osama bin Laden, who masterminded the September 11 terrorist attacks.
    The Taliban offered to hand over bin Laden for trial, but only to a third country, rather than directly to the United States. Washington refused the offer and launched air and ground attacks, joined shortly thereafter by US allies.
    Attempts to stabilize the country and enable a US exit have faltered however, with surges, counter-insurgency operations, and economic projects making little headway.
    US troop deployment to Afghanistan peaked in August 2010 at 100,000. At present there are around 9,000 US soldiers in the country, along with smaller detachments of NATO troops.