请教国贸专业的同学几个问题，希望能详细解答,多谢了！！！！Thank you very much!

1. In recent cases, the U.S. placed quotas or protectionist tariffs on imported steel and imported microchips. In both cases the damage to "downstream" industries was obvious to all and relatively easy to quantify and demonstrate. Assuming that the U.S. lawmakers are not plain dumb, why did they enact these protectionist policies?

2. The U.S. is probably the most open international market among the industrialized countries. What then does the U.S. have to gain by joining the WTO?