Why is it necessary?
I know what you are saying. I recoil each time I see a foreign company on our shores.
I'm sorry to say that I cannot answer, other than to say it is the world we are living in today.
I will say, that although there are traitorous Americans in positions of power, I am not seeing this as a move by them.
Let us see how this plays out.
"The United States maritime borders include 95,000 miles of open shoreline, 361 ports and an Exclusive Economic Zone that spans 3.5 million square miles. The United States relies on ocean transportation for 95 percent of cargo tonnage that moves in and out of the country. Each year more than 7,500 commercial vessels make approximately 51,000 port calls, and over six million loaded marine containers enter U.S. ports. Current growth predictions indicate that container cargo will quadruple in the next twenty years."
From ... http://www.house.gov/transportation/cgmt/03-13-02/03-13-02memo.html