Senator Rand Paul [R-KY] has let it be known that he will propose a joint resolution to declare war against the so-called Islamic State. While the measure looks like a normal one for that purpose, in fact it is highly unusual, and for puzzling reasons that are not explained.
First, it is against the "organization" known as IS. Most declarations of war are against other countries -- except for the 2001 authorization of military force against those connected to the 9/11 attacks, which -- nota bene -- was not actually a declaration of war.
Second, Paul's proposal expires after one year. No other declaration of war in U.S. history has had a time limit.
Third, it tries to limit the use of ground troops except for highly limited operations including rescue of U.S. personnel and attacks on "high value targets." Its actual wording, however, doesn't forbid other ground operations; it only declares that the resolution isn't supposed to be "construed" as allowing them. That's a pretty big loophole.
Fourth, it's especially surprising that a Republican Senator, one of many who has criticized President Obama for broadening executive powers in both domestic and foreign affairs, would use the "w word" -- war -- and thereby trigger a vast array of presidential powers exclusive to a time of war. Those powers include presidential control of trade, transportation, communications, and manufacturing. A declaration of war also suspends for up to 15 days the requirement for a court order for electronic surveillance and physical searches under the Foreign Intelligence Surveillance Act.
A CRS study gives some examples. A declaration of war "give[s] the President the authority to order plants to convert to the production of armaments and to seize those that refuse to do so, to assume control of transportation systems for military purposes, to condemn land for military uses, to have the right of first refusal over natural resources, and to take control of communications facilities.It also gives the President full power over agricultural exports. An authorization for the use of force, in itself, does not trigger any of these authorities."