The situation came to a head in 1839. Dost Mohammad Khan’s new friendship with the Russians worried the British, but even more worrisome was his political prowess. The area under his control was, at its greatest extent, larger than the boundaries of Afghanistan today, and he expanded his regional influence throughout his rule. In addition to his contact with Russia, Dost Mohammad Khan allied with Iran in an attempt to take control of Punjab, an area firmly in the British sphere. The British understood that these imperial ambitions threatened to destabilize the region even without Russian interference.