I am an Indian citizen. I have a valid U.S. work visa. However, my next project allocation is in the UK. Will my U.S. visa become invalid if I travel to the UK (before travelling to the U.S.) ?
There are specific rules by which a US Visa can be revoked. If your trip to the UK will make you fit the criteria for revocation (e.g. you're going to shoot up US embassy or consulate) then the answer to your question is definitely yes.