What are those best interests? In this case the Trump administration wanted to protect Boeing against Bombardier by denying access to a key market, making Bomb

What are those best interests? In this case the Trump administration wanted to protect Boeing against Bombardier by denying access to a key market, making Bombardier's entire C-* project unprofitable. The outcome (so far) is that Airbus/Bombardier can still make the airplane and export to any country from either Canada or the US, whichever has the best trade conditions. This does not sound favourable for Boeing's export business. AIUI this isn't an unusual outcome: A government wants to protect domestic business against imports, accidentally hurts its own exports and offends someone in the process. The domestic business may be its best interest but that's hardly obvious.