Retailers have woken up to yet another tariff nightmare as a fresh round of trade barriers have this time been blamed on labor practices by the Trump administration.

U.S. Trade Representative Jamieson Greer telegraphed that the Trump administration could impose new tariffs just as other duties are set to expire.

The move illustrates the White House's determination to sustain its tariff agenda.

To dig into the reasoning behind these tariffs and what they mean for the global economy, we turned to our leading tariff watchers.