The Office of Foreign Assets Controls is demonstrating that its bite is as big as its bark.

The watchdog agency, which is part of the Treasury Department and is responsible for administering and enforcing violations of economic and trade sanctions, is increasingly pursuing companies that violate the rules with more aggressive and broader enforcement than in past years. It recovered more than $1 billion in fines and penalties from 2009 to 2010 for sanction violations—a significant increase from the $5 million recovered in all of 2007 and 2008. And the pace is only quickening.

“The government is simply better organized ...