Let them try. So long as they stand out of the way and just protest; not blocking the recruiters or access of those who wish to see the recruiters they are ok. If however they impede the recruiters now they fall under this:
U.S. Code
TITLE 18
PART I
CHAPTER 115
§ 2388. Activities affecting armed forces during war
(a) Whoever, when the United States is at war, willfully makes or conveys false reports or false statements with intent to interfere with the operation or success of the military or naval forces of the United States or to promote the success of its enemies; or
Whoever, when the United States is at war, willfully causes or attempts to cause insubordination, disloyalty, mutiny, or refusal of duty, in the military or naval forces of the United States, or willfully obstructs the recruiting or enlistment service of the United States, to the injury of the service or the United States, or attempts to do so-
Shall be fined under this title or imprisoned not more than twenty years, or both.
(b) If two or more persons conspire to violate subsection (a) of this section and one or more such persons do any act to effect the object of the conspiracy, each of the parties to such conspiracy shall be punished as provided in said subsection (a).
(c) Whoever harbors or conceals any person who he knows, or has reasonable grounds to believe or suspect, has committed, or is about to commit, an offense under this section, shall be fined under this title or imprisoned not more than ten years, or both.
(d) This section shall apply within the admiralty and maritime jurisdiction of the United States, and on the high seas, as well as within the United States.
Yes we are legally at war both the WAR on Terror and Against the Same folks in IRAQ and in Iraq to begin with as APPROVED BY both the HOUSE and THE SENATE by a CLEAR OVERWHELMING MAJORITY of votes from each Chamber.