Right now we are seeing a classical "fire attack" launched by FedEx on UPS using the government as a proxy. Sun Tzu's spends an chapter discussing the concept of "fire attacks," where an opponent uses the environment to attack an opponent and we devote and entire section of The Rule Book to the issues he raises regarding vulnerability. Quoting the introductory article in the Warrior's Rule Book on the topic (9.0 Using Vulnerability):
In the modern world, instead of attacking competitors with fire, rivals use the government, the media, or special interest groups such as a consumer, civil rights or environmental groups to do their work for them. Law suits, government investigations, and bad publicity are the fire attacks of the modern world.
Below is a great video from Reason.TV explains how interdependent politics and business have become on this level. Thanks to InstaPundit and the Washington Examiner article discussing this battle. To quote the most relevant statement in the video:
Is it fair for FedEx and UPS to play by different rules? Is it fair to change the rules on FedEx in the middle of the game? Is the NLRA even fair?
Sadly, "fair competition," doesn't really play a role in shipping--an industry that has been subsidized and regulated since its birth. Federal law nearly prohibits UPS and FedEx from competing on price. Other regulations--including labor laws--cramp their ingenuity.