Trump says that imports pose a threat to USA (with a 3.8% unemployment rate )???

POTUS Trump says that imports pose a threat to American national security. If these imports are a threat....how come the USA is doing so well economically? Their unemployment rate is at the lowest in a long time...at 3.8%. That means that 96.2% of people are working. Most economists will probably tell you that this level is basically full employment. So where is the threat to national security? If the imports were a threat, then one would expect the unemployment rate to be hurt by these imports. But POTUS Trump is running the USA as a CEO....who sees only that his "USA business" is buying more that it is selling...therefore thinking that he is losing money. POTUS Trump is running USA as a Caesar...who believes in serving and magnifying himself...claiming this to be right, his will & right, in the name of FREEDOM.