The Hindu–German Conspiracy failed to engage popular support within India. However, it had a significant impact on Britain's policies both in the empire, as well as on her international relations. The outlines and plans for the nascent ideas of the conspiracy were noted and began to be tracked by the British intelligence as early as 1911. Alarmed at the agile organisation, which repeatedly reformed at different parts of the country despite being subdued in others, the chief of Indian Intelligence Sir Charles Cleveland was forced to warn that the idea and attempt at pan-Indian revolutions were spreading through India "like some hidden fire". A massive, concerted and coordinated effort was required to subdue the movement. Attempts were made in 1914 to prevent the naturalisation of Tarak Nath Das as an American citizen, while successful pressure was applied to have Har Dayal interned. The conspiracy had been detected early by British intelligence, and had been the subject of strong British pressure from 1914.
Background
World War I began with an unprecedented outpouring of loyalty and goodwill towards the United Kingdom from within the mainstream political leadership, contrary to initial British fears of an Indian revolt. India contributed massively to the British war effort by providing men and resources. About 1.3 million Indian soldiers and labourers served in Europe, Africa, and the Middle East, while both the Indian government and the princes sent large supplies of food, money, and ammunition. However, Bengal and Punjab remained hotbeds of anti-colonial activities. Terrorism in Bengal, increasingly closely linked with the unrests in Punjab, was significant enough to nearly paralyse the regional administration. Also from the beginning of the war, expatriate Indian population, notably from United States, Canada, and Germany, headed by the Berlin Committee and the Ghadar Party, attempted to trigger insurrections in India on the lines of the 1857 uprising with Irish Republican, German and Turkish help in a massive conspiracy that has since come to be called the Hindu–German Conspiracy This conspiracy also attempted to rally Afghanistan against British India. A number of failed attempts were made at mutiny, of which the February mutiny plan and the 1915 Singapore Mutiny remains most notable. This movement was suppressed by means of a massive international counter-intelligence operation and draconian political acts (including the Defence of India Act 1915) that lasted nearly ten years.
Political impact
The Conspiracy, judged by the British Indian Government's own evaluation at the time, and those of a number of contemporary and modern historians, was one of the most important events in the Indian independence movement and was one of the most significant threats to have faced the Raj in the second decade of the 20th century.
In India
The conspiracy, especially in the scenario of the British war effort and the threat from the militant movement in India, was the major factor for the passage of the Defence of India Act 1915. Among the strongest proponents of the act was Michael O'Dwyer, then the Lieutenant Governor of Punjab, and this was largely due to the Ghadarite movement.
It is now judged to have been the principal factor guiding British political concessions as well as Whitehall's India policy during and after World War I, including the passage of Montagu–Chelmsford Reforms. It has also been suggested by a number of historians that the events, especially in Punjab, in 1919 owed to a large extent to the Ghadarite movement or what was left of it, the presence of Pratap's Kabul mission in Afghanistan its overtures towards Bolshevik Russia, and the Raj's perception of its potential was a key factor, in spurring political progression in India. In 1917, the Montagu–Chelmsford Reforms initiated the first rounds of political reform in the Indian subcontinent. At the same time, a Sedition Committee chaired by Sydney Rowlatt, an English judge, was instituted in 1918 which evaluated the Indo-German-Ghadar link and the militant movement in India. On the recommendations of the committee, the Rowlatt Act, an extension of the Defence of India Act 1915, was enforced in response to the threat in Punjab and Bengal.