Alan D. Bersin, commissioner of the 57,000-employee U.S. Customs and Border Protection, will resign effective December 30, he said Thursday. Bersin was appointed to the post by President Barack Obama on March 27, 2010. He notified the president of his resignation Thursday, he said in a statement. "My service as commissioner has been one of the most rewarding experiences of my public life," Bersin said. "I am immensely proud of the significant and meaningful achievements we have made on our borders and at our nation's ports of entry over nearly two years. "Through innovative solutions and strengthened partnerships, we have...