India, July 12 -- Argentina are through to another World Cup semifinal. That much is certain. Yet almost everything about how they got there should worry Lionel Scaloni.

Three knockout games. Three occasions on which Argentina were pushed to the brink. Two went into extra time. In all three, the defending champions stared elimination in the face before finding a way out. The most striking part? They have reached the semifinals without facing a top-10 side. That makes the recurring defensive alarms impossible to ignore.

It began against Cape Verde in the Round of 32. The tournament debutants came within minutes of taking the defending champions to penalties after Sidny Lopes Cabral curled a stunning right-footed strike into the top corne...