As U.S. President Donald Trump left India after a largely unsuccessful visit last week, Sen. Bernie Sanders, the front-runner for the Democratic nomination, expressed himself on the subject with his accustomed vehemence. "Instead of selling $3 billion in weapons to enrich Raytheon, Boeing and Lockheed, the United States should be partnering with India to fight climate change," he tweeted. Sanders added: "We can work together to cut air pollution, create good renewable energy jobs, and save our planet."

Two parts of this tweet deserve attention. We can dispose of the first quickly: By the standards of international defense deals, $3 billion is not a lot, and the U.S. defense industry continues to view India as a missed opportunity.

The second and more worrying point made by Sanders is about "partnering with India to fight climate change." This is a wonderfully warm and fuzzy sentiment. Yet there's nothing in Sanders's platform to back it up — in fact, quite the reverse.