they can always go back to their famous opium trade and use their gunboat diplomacy if any countries refused to open their country to British opium trade.
http://www.amoymagic.com/OpiumWar.htm
European opium smugglers flirted with China’s death penalty as early as 1729, for opium’s immense profits were more addictive than the poppy. The only problem was supply, which Britain solved in 1756 by conquering Calcutta.
Clive marveled at India, the “rich and Lin Zexu who fought the opium tradeflourishing kingdom.” Within decades that rich kingdom was pauperized as farmers were forced to abandon traditional crops and to grow what became the Crown’s primary cash crop, and China’s main import—opium.
Warren Hastings, India’s first governor-general, wrested control of the Dutch opium trade, rapidly expanded poppy production, and dispatched two opium-laden ships to Canton on a trial run. One was shipwrecked, but the other evaded Chinese officials and sold 200,000 pounds of opium in Huangbo.
in order for currency depreciation to work its magic, more demand for exports must be forthcoming when the exchange rate falls (or, as economists say, the price elasticity of demand for exports must be high). But various studies have shown that the price elasticity of demand for UK exports is low. For example, a recent paper by Francesco Aiello, Graziella Bonanno, and Alessia Via of the European Trade Study Group finds that “the long-run level of exports appears to be unrelated to the real exchange rate for the UK.”