U.S. President Donald Trump's suggestion that South Korea will have to foot the $1.1 billion bill for the Terminal High Altitude Area Defense (THAAD) system being placed in its territory amounts to only a minor addition to the long list of controversies spurred by the deployment. The president's comments sparked a flurry of conversations over the weekend between South Korean and U.S. officials, who downplayed the statement. And in the short term, the results of South Korea's presidential election and the objections China has raised about the THAAD's effect on its own security will have a greater impact on the long-term prospects of the U.S. missile defense system intended to counter North Korea's thriving ballistic missile program....