Global markets got a glimpse of the unthinkable Wednesday when the U.S. held a key bond auction. The $27 billion sale of 10-year notes – the world’s benchmark securities – didn’t go well at all. It wasn’t a failure; that would have triggered no less than an Armageddon-type event on par with the financial crisis. But the poor demand sure sparked a lot of questions, including whether this was a sign that investors finally had enough of the government’s profligate spending and borrowing.