A former New Zealand government adviser says Japan's decision to restart commercial whaling has been influenced by Donald Trump.
International environment law Professor Al Gillespie says Japan has followed Mr Trump's lead in putting its own interests ahead of the environment. He fears it sets a precedent that could undo decades of progress.
The decision has triggered debate among conservationists about how it will impact whale numbers globally. But Prof Gillespie says the implications go beyond conservation.
"The big risk here is precedent, where one country decides it doesn't want to work with international environmental law," Prof Gillespie says.
"We recently saw that from Trump and the Paris Compact and climate change."
He says Japan has followed Mr Trump's lead.
"Our fear is that it could become a precedent for other countries to walk away, not just from the whaling debate, from any other environmental issue that they don't agree with."
The worst-case scenario is the breakdown of the International Whaling Commission (IWC) altogether and the return of "free for all" whaling, Prof Gillespie says.
Currently Japan's withdrawal from the IWC actually benefits some conservation programmes.
It means proposed global whale sanctuaries that were being held back are now likely to go ahead and it signals the end of so-called 'scientific whaling' in the Antarctic.
"We've seen some recovery in some populations whilst the ban on commercial whaling has been in place but if we see an outbreak, if we see a return to the old lawless days, then I think we have to fear for the worst," says Mark Simmonds, senior marine scientist of the International Human Society.