Biplane crop duster over an American soybean field, 2010. Photograph by Ken Hammond, U.S. Department of Agriculture.

The weather finally turned crisper in the Northeast thanks to cooler air moving into the region from Canada.

I hope it didn’t have to pay a tax at the border or maybe surrender its son, Cool Air Jr.

You have to worry about everything and everyone crossing the American borders these days. On Friday, President Donald J. Trumpet imposed tariffs of 25 percent on 800 Chinese goods coming into the U.S. while China imposed tariffs on soybeans, corn and pork, which hurts American farmers, who largely went for Trump in the last election. Talk about cutting off your nose to spite your face.

The fact is that the world is, as someone put it to me so wisely recently, “a large place that returns small.” The connection between local economies and the global one is so strong that everything has a ripple effect, particularly on jittery Wall Street. But there’s something else to consider, David Honig, an attorney who teaches negotiations at Indiana University, told the “PBS NewsHour’s” Amna Nawaz on Friday:

“So, what we see is, we not only see damage to American farmers, because they’re not able to sell their soybeans, but what happened next is, China bought their soybeans from Russia. They tripled their purchases from Russia.

“The ripple effect beyond that is not only is Russia now buying soybeans, selling soybeans and American farmers are losing them, but Russia is now getting hard currency. So, if you go outside trade and look at America’s ability to project its power, now sanctions are going to be less effective, because our sanctions addressed at Russia go to limiting their availability for hard currency, and we put them in a situation where they can get more of that from China.”

I don’t think Trump cares. He’s probably happy for Russia and his pal Putin.

Indeed, he seems to be more interested in Putin than in the economic fate of the people who voted for him, let alone the rest of America.