Final answer:
The Second Opium War (1856-1860) started over conflicts about a British-registered ship and resulted in the bombardment of the Chinese coast by British and French forces. It ended with treaties that significantly expanded European trade rights and continued the weakening of the Qing dynasty's control.
Step-by-step explanation:
The Second Opium War erupted in 1856 when a Chinese captain refused to give up suspected pirates on a British-registered ship to the British officials. The British demanded the release of the ship and crew, along with an apology, which China rejected. This led to the British naval forces bombarding the Chinese coast, with the French joining in, aiming for greater access to the Chinese markets. Although the United States and Russia offered limited support, they weren't formally part of the alliance. The war's hallmark were European raids that devastated the Chinese coast and exposed the weakening Qing dynasty, without threatening China's existence.
Like the First, the Second Opium War was about forcing China open to Western trade, particularly the opium trade from India. It culminated in the Treaty of Tianjin, which granted further trading rights to foreigners, and the Convention of Beijing after China's defeat, solidifying foreign control over trade and heralding increased European influence within China. This conflict, too, resulted in another European victory and led to the systematic undermining of the Qing dynasty's authority, marking a momentous shift in East Asian international relations dominated previously by China.