Trust me, we would if we could. The Marine Mammal Protection Act currently prevents the importation of marine mammals with depleted populations, which includes polar bears. Otherwise, American zoos would scoop up Canadian bears in a heartbeat and reverse the decline of our captive population.
No apparently US laws make it much more difficult than that. Any rescued cub belongs to US Fish and Wildlife and the law prohibits them from breeding unless a special exception is made. I don't claim to know all the ins and outs of it but getting Alaskan polar bears and having them breed is much trickier than in Canada. It has to do with the US laws surrounding marine life and endangered animals. US zoos if they had their choice would love to take in Canadian bears, either wild born or captive born. Canadian bears are out due to import restrictions. If I recall correctly the fact they are marine life, endangered in the US and the fact Canada allows the hunting of polar bears are all factors. If they could adopt young Canadian bears to boost the population they would in a heart beat.
