Trade negotiations used to be underpinned by an unspoken assumption: that trade barriers were lose-lose propositions. All sides could gain something if they mutually disarmed.
Each country would agree to lower its tariffs, a little or a lot, in return for others doing likewise. Trade negotiations were always about how much tariffs and other walls would go down, not how much they would go up.
Trade deals hollowed out manufacturing in Canada and the US, no one but the connected made money.
