During a multiple entry Tourist Visa (B1/B2) period, my wife obtained a Green Card. After about 5 years, she surrendered her Green card at a US Consulate in India.
At this point in time, her multiple entry Tourist Visa (B1/B2) has a validity of about 3 years. The Tourist Visa (B1/B2) was not marked as 'Cancelled'. In this situation, if she wants to travel to the US, is it necessary for her to apply for a new multiple entry Tourist visa (B1/B2) or can she travel using her existing Tourist Visa?