A reader writes:
The language you quoted isn't the worst of it. It does require "material support," and that would presumably be defined as in 18 USC 2339a:
(1) the term "material support or resources" means any property, tangible or intangible, or service, including currency or monetary instruments or financial securities, financial services, lodging, training, expert advice or assistance, safehouses, false documentation or identification, communications equipment, facilities, weapons, lethal substances, explosives, personnel (1 or more individuals who may be or include oneself), and transportation, except medicine or religious materials;
(2) the term "training" means instruction or teaching designed to impart a specific skill, as opposed to general knowledge; and
(3) the term "expert advice or assistance" means advice or assistance derived from scientific, technical or other specialized knowledge.
This is harsh, but not out-of-bounds for law of armed conflict. No, the choking point is the second part of the definition in which the Executive simply gets to say who such an illegal enemy combatant is. That is, in its essence, tyrannical. They say "trust us," but why should we? We now see a long track record of people being so classified and held with little or no basis. The exercise of the discretion has, in other words, been corrupt.
The deeper point is that, in this law, the "battlefield" has been extended into every living room in the country, and that without judicial oversight, the entire discretion to name someone an "illegal enemy combatant" is entirely up to one man, the president. And he also has the discretion to torture such a person at will, using techniques once deployed by the North Vietnamese and the KGB. This is the bill now being considered. It is a grave threat to basic liberties.