Representative Ron Paul of Texas once again schools the Executive Branch on the Constitution. Instead of waging undeclared war on nations Mr. Paul suggests the issuance of a Letter of Marque and Reprisal against named terrorists and their assets.
A Letter of Marque and Reprisal is an official warrant or commission from a national government authorizing the designated agent to search, seize, or destroy specified assets or personnel belonging to a party which has committed some offense under the laws of nations against the assets or citizens of the issuing nation, and has usually been used to authorize private parties to raid and capture merchant shipping of an enemy nation.
This power is of course delegated specifically to the Congress and not the President, possibly explaining Mr. Bush's reluctance to ask for the use of such a tool. He doesn't really pay much attention to the enumerated powers of any given branch and assumes those powers(and some he just makes up) reside with the Executive.
This congressional power was originally used to battle piracy and other acts by individuals or groups not representing any government. Hmmmmm...sounds kinda like terrorist groups.
The Letters allowed the government to take retaliatory action without having to declare war especially in situations where there was no nation upon which to declare war.
As with a domestic search, arrest, seizure, or death warrant, to be considered lawful it needs to have a certain degree of specificity, to ensure that the agent does not exceed his authority and the intent of the issuing authority.
The specificity clause, is probably another reason W hasn't pursued the idea of the Letters.
In October 2001, Paul introduced a bill to issue Letters of Marque against those responsible for 9/11 (it didn't pass) and has re-introduced the bill again recently.
Ron Paul has long been a champion of the Constitution as this video nicely illustrates: