The oil industry has also developed remotely-operated vehicles to make trenches for seabed pipelines, which can be adapted for cutting ore, even though it may lie much deeper, at, say, 1.5km down.

It has met some resistance from developed nations like Australia in its quest to buy up mining and iron ore assets, but has been largely successful in Africa.

Second, the US and its western Allies have a vital interest in strategic materials, like mineral and ore, which have to be imported from less-developed countries like the Philippines.