Some historians claim that Lord Palmerston, the British Foreign Secretary, initiated the Opium War to maintain the principle of free trade. Professor Glenn Melancon, for example, argues that the issue in going to war was not opium but Britain's need to uphold its reputation, its honour, and its commitment to global free trade. China was pressing Britain just when the British faced serious pressures in the Near East, on the Indian frontier, and in Latin America. In the end, says Melancon, the government's need to maintain its honour in Britain and prestige abroad forced the decision to go to war. Former American president John Quincy Adams commented that opium was "a mere incident to the dispute ... the cause of the war is the kowtow—the arrogant and insupportable pretensions of China that she will hold commercial intercourse with the rest of mankind not upon terms of equal reciprocity, but upon the insulting and degrading forms of the relations between lord and vassal."
The most recent version is by Australian historian Harry G. Gelber who argues that opium played a role similar to the tea dumped into the harbor in the Boston Tea Party Of 1773 leading to the American Revolutionary War. Gelber argues instead that:
Western women were not legally permitted to enter China in the first place. Into the 19th century, Western nations did not recognise diplomatic equality for entities that failed to meet their "standard of civilisation", including China.
The policy of restricting trade to a single port was also used in Western countries such as Spain and Portugal. Western merchants could also trade freely and legally with Chinese merchants in Xiamen and Macao, or when the trade was conducted through ports outside China such as Manila and Batavia.
The public in Western countries had earlier condemned the British government for supporting the opium trade. By 1850, opium smuggling to China accounted for up to 20% of the revenue of the British Empire, serving as the most profitable single commodity trade of the 19th century. As Timothy Brook and Bob Wakabayashi write of opium, “The British Empire could not survive were it deprived of its most important source of capital, the substance that could turn any other commodity into silver.”
Chinese merchants were actually banned by Qing law from suing foreigners in Chinese courts, as the Qianlong Emperor believed that good treatment of foreigners was essential for the government. The Qianlong Emperor granted Lord Macartney a golden scepter, an important symbol of peace and wealth, but this was dismissed by the British as worthless. In 1806, Chinese officials compromised with the British on the murder of a Chinese man by British seamen, as Westerners refused to be punished under Chinese law, and local citizens vigorously protested what they considered a miscarriage of justice. In 1816, the Jiaqing Emperor dismissed a British embassy for their refusal to kowtow, but he sent them an apologetic letter with gifts (the British simply discarded them in a storeroom without reading). The British, on the other hand, ignored Chinese laws and warnings not to deploy military forces in Chinese waters. The British landed troops in Macao despite a Chinese and Portuguese agreement to bar foreign forces from Macao, and then in the War of 1812 attacked American ships deep in the inner harbour of Canton (the Americans had previously robbed British ships in Chinese waters as well). These, in combination with the British support to Nepal during their invasion of Tibet and later the British invasion of Nepal after it became Chinese tributary state, led the Chinese authorities to become highly suspicious of British intentions. In 1834, when British naval vessels intruded into Chinese waters again, the Daoguang Emperor commented: "How laughable and deplorable is it that we cannot even repel two barbarian ships. Our military had decayed so much. No wonder the barbarians are looking down on us."
Historians have often pondered whether the war could have been avoided. One factor was that China rejected diplomatic relat