Whoever enlists or is engaged within the United States or in any place subject to the jurisdiction thereof, with intent to serve in armed hostility against the United States, shall be fined under this title  or imprisoned not more than three years, or both.
18 U.S. Code § 2390. Enlistment to serve against United States
Based on title 18, U.S.C., 1940 ed., § 8 (Mar. 4, 1909, ch. 321, § 8, 35 Stat. 1089).
Mandatory punishment provision was rephrased in the alternative.
Minor changes were made in phraseology.
1994—Pub. L. 103–322, which directed the amendment of this section by striking “fined not more than $100” and inserting “fined under this title”, was executed by substituting “fined under this title” for “fined $100”, to reflect the probable intent of Congress.
 See 1994 Amendment note below.