They've encountered and traded with people from outside the island, like Anstice Justin during contact attempts between the 80s and 2000s [0]. The direct contact attempts were halted in the 90s due to ethical/health concerns for the sentinelese though, so expeditions after that point were gift-giving missions to monitor and support friendly relations.
They became more hostile to expeditions after some fishermen were killed on the island and recovery teams attempted to use helicopters to rescue the bodies before the islanders could bury them.
They became more hostile to expeditions after some fishermen were killed on the island and recovery teams attempted to use helicopters to rescue the bodies before the islanders could bury them.
[0] https://www.nature.com/articles/d44151-024-00213-5