For nearly two decades, the idea of an American deep-water Arctic port has been on paper only, passed around in congressional hearings, quietly shelved by budget realities and periodically revived as alarm about Russian and Chinese activity in the Arctic grew louder.

Now, after a series of landmark legislative actions, executive decisions and a construction contract worth nearly $400 million, Alaska’s ports are at the centre of a transformation that could redefine American power in the world’s most contested emerging ocean.