I am looking for a word or phrase meaning a product which fundamentally changes a society. Examples:
- The iPhone popularized smart-phones in the United States, transforming the country to rapidly become much more connected.
- The introduction by the British East India Tea Company of opium to China catalyzed social unrest and ultimately lead to the First Opium War, leading to the ceding of Hong Kong.
My question is similar to this one, which asked for words/phrases describing the opportunity to have a significant impact on a society. The principal difference is that I am looking for a word or phrase that means a tangible good/product/export/commodity which has this affect.
Portuguese firearms proved a ______ in the Sengoku Period of Japan, permanently changing the operation of war in that country thereafter.