In their homeland which we polluted, hence all the health problems that  rose after we dropped 67 nuclear bombs over the course of 12 years, rendering parts of the islands still uninhabitable. I wold prefer we spend the money to fix their homelands and provide medical care, but Congress thought the compact was a better route. But the notion that shouldn't be let in because they cannot contribute by whatever definition you use, ignores the moral obligation we have. http://www.businessinsider.com/marshall-islands-nuclear-bombs-radiation-2016-6