For every action, there is an equal and opposite reaction.
It's as true in physics as it is in public policy and trade laws.
So we understand why much of the country holds reservations over potential international economic fallout from President Donald Trump's proposed 25 percent tariff on foreign-produced steel.
After Trump told steel executives Thursday he plans to impose the tariff, the Wall Street markets dipped and industries that consume steel have warned the tariffs would lead to higher prices that would hurt manufacturers and consumers alike.
To the critics, the "equal and opposite" reaction is an economic strain in many sectors.
But to consider the full argument, we all must look at the struggle our domestic steel industry — still a major economic force in Northwest Indiana — has faced under the practice of illegally "dumped" foreign steel into the American markets.
Those skyrocketing steel imports, for which Chinese steel companies have been a major culprit, have contributed to the closing of 10 blast furnaces, including a few at ArcelorMittal Indiana Harbor in East Chicago, in the past two decades.
A federal probe rightly has concluded that elevated foreign steel import levels threaten the survival of our domestic steel industry as well as our national security.
U.S. House Rep. Pete Visclosky, D-Gary, has been a steadfast champion of the Northwest Indiana steel industry.
He is calling on Trump to make good on his tough talk of imposing the new sweeping 25 percent tariff.
It may sting in other sectors, but we must have a level playing field for what remains a major industry that is vital to the literal skeleton upon which our city's and infrastructure are built.
It's time for our nation's highest leaders to act in defense of our own steel industry — not continue to ignore unscrupulous foreign interests that unfairly erode American assets.