There are some interesting discussions in Holder v. Humanitarian Law Project on the First Amendment and National Security law.

From Chief Justice Robert’s majority opinion:

That evaluation of the facts by the Executive, like Congress’s assessment, is entitled to deference. This litigationimplicates sensitive and weighty interests of national security and foreign affairs. The PKK and the LTTE have committed terrorist acts against American citizens abroad,and the material-support statute addresses acute foreign policy concerns involving relationships with our Nation’s allies. See id., at 128–133, 137. We have noted that “neither the Members of this Court nor most federal judgesbegin the day with briefings that may describe new and serious threats to our Nation and its people.” Boumediene v. Bush, 553 U. S. 723, 797 (2008). It is vital in this context “not to substitute . . . our own evaluation of evidence for a reasonable evaluation by the Legislative Branch.” Rostker v. Goldberg, 453 U. S. 57, 68 (1981). See Wald, 468 U. S., at 242; Haig v. Agee, 453 U. S. 280, 292 (1981).

Our precedents, old and new, make clear that concernsof national security and foreign relations do not warrantabdication of the judicial role. We do not defer to the Government’s reading of the First Amendment, even when such interests are at stake. We are one with the dissent that the Government’s “authority and expertise in these matters do not automatically trump the Court’s own obligation to secure the protection that the Constitutiongrants to individuals.” Post, at 23. But when it comes to collecting evidence and drawing factual inferences in this area, “the lack of competence on the part of the courts ismarked,” Rostker, supra, at 65, and respect for the Government’s conclusions is appropriate.

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All this is not to say that any future applications of the material-support statute to speech or advocacy will survive First Amendment scrutiny. It is also not to say that any other statute relating to speech and terrorism would satisfy the First Amendment. In particular, we in no waysuggest that a regulation of independent speech would pass constitutional muster, even if the Government wereto show that such speech benefits foreign terrorist organizations. We also do not suggest that Congress could extend the same prohibition on material support at issuehere to domestic organizations. We simply hold that, in prohibiting the particular forms of support that plaintiffs seek to provide to foreign terrorist groups, §2339B does not violate the freedom of speech.

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The Preamble to the Constitution proclaims that the people of the United States ordained and established that charter of government in part to “provide for the common defence.” As Madison explained, “[s]ecurity against foreign danger is . . . an avowed and essential object of the American Union.” The Federalist No. 41, p. 269 (J. Cooke ed. 1961). We hold that, in regulating the particular formsof support that plaintiffs seek to provide to foreign terrorist organizations, Congress has pursued that objective consistent with the limitations of the First and Fifth Amendments.

From Justice Breyer’s dissenting opinion:

Not even the “serious and deadly problem” of interna-tional terrorism can require automatic forfeiture of First Amendment rights. §301(a)(1), 110 Stat. 1247, note fol-lowing 18 U. S. C. §2339B. Cf. §2339B(i) (instructingcourts not to “constru[e] or appl[y the statute] so as toabridge the exercise of right guaranteed under the First Amendment”). After all, this Court has recognized thatnot “‘[e]ven the war power . . . remove[s] constitutional limitations safeguarding essential liberties.’” United States v. Robel, 389 U. S. 258, 264 (1967) (quoting Home Building & Loan Assn. v. Blaisdell, 290 U. S. 398, 426 (1934)). See also Abrams v. United States, 250 U. S. 616, 628 (1919) (Holmes, J., dissenting) (“[A]s against dangers peculiar to war, as against others, the principle of theright to free speech is always the same”). Thus, there is no general First Amendment exception that applies here.If the statute is constitutional in this context, it would have to come with a strong justification attached.

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In sum, these cases require us to consider how to applythe First Amendment where national security interestsare at stake. When deciding such cases, courts are awareand must respect the fact that the Constitution entrusts tothe Executive and Legislative Branches the power to provide for the national defense, and that it grants par-ticular authority to the President in matters of foreignaffairs. Nonetheless, this Court has also made clear that authority and expertise in these matters do not automati-cally trump the Court’s own obligation to secure the pro-tection that the Constitution grants to individuals. Cf. Hamdi v. Rumsfeld, 542 U. S. 507, 536 (2004) (“We have long since made clear that a state of war is not a blank check . . . when it comes to the rights of th[is] Nation’s citizens”). In these cases, for the reasons I have stated, I believe the Court has failed to examine the Government’s justifications with sufficient care. It has failed to insist upon specific evidence, rather than general assertion. It has failed to require tailoring of means to fit compelling ends. And ultimately it deprives the individuals before usof the protection that the First Amendment demands.