Answer:
Guwahati, Dec 20: Bhutan had last gone to war against any foreign force 138 years ago. That was the Anglo-Bhutanese war of 1865. The British, having already established control in Bengal, had set their eyes on Bhutan to boost trading with Tibet. That aside, the British were stung by the frequent Bhutanese incursions into Cooch Behar. Under Warren Hastings, the British compelled Sonam Lhendup, Bhutan’s then Deb Raja or the temporal head, to sign a treaty in 1744, extracting an assurance that Guwahati, Dec 20: Bhutan had last gone to war against any foreign force 138 years ago. That was the Anglo-Bhutanese war of 1865. The British, having already established control in Bengal, had set their eyes on Bhutan to boost trading with Tibet. That aside, the British were stung by the frequent Bhutanese incursions into Cooch Behar. Under Warren Hastings, the British compelled Sonam Lhendup, Bhutan’s then Deb Raja or the temporal head, to sign a treaty in 1744, extracting an assurance that the Bhutanese would not raid British
The agreement was not followed for long as the Deb Raja was weak and soon lost control over affairs. Bhutan saw the emergence of a number of factional leaders, some of whom started attacking British possessions in Bengal and Assam. The British were bent on installing a strong ruler in Bhutan. Finally, in 1865, a war was declared in which the Bhutanese were defeated. This enabled the Crown to exercise a lot of influence in Bhutan’s affairs.
This may be ancient history, but that was the last time that Bhutan battled a foreign force until King Jigme Singye Wangchuk put his small military on the trail of a band of 3,000 or more Indian separatist rebels at the crack of dawn on December 15 to expel them out of the kingdom. This may not be a conventional war, but nonetheless it is nothing short of one in so far as the inexperienced Royal Bhutan Army (RBA) and the Royal Bhutan Guards (RBG) are concerned.