That the killing of Iranian Maj. Gen. Qasem Soleimani will reorder the Middle East is obvious — Iraq’s parliamentary vote to expel U.S. forces, along with Iran’s declared restarting of its nuclear arms program with “no limitations,” offers proof enough. But that the killing will have repercussions within the United States, rattling the lives and liberties of many U.S. citizens and residents, is also a strong possibility — one that’s no less ominous.

Already, there are harbingers of a potential crackdown on Iranian Americans. On Sunday, U.S. citizens of Iranian origin returning to the United States from Canada via the Peace Arch Border Crossing in Blaine, Wash., were detained and questioned for up to 10 hours. Asked why, one was told by a border official, “This is a bad time to be an Iranian,” according to an official with the Council on American-Islamic Relations (CAIR) who had talked with the travelers.

How “bad” might it get if hostilities with Iran accelerate? The legal foundations for punitive action against Iranian Americans already exist. Since 2001, the executive branch has stockpiled arguments for abrogating the liberties of “suspect” populations. In response, Congress and the courts have competed over which can be more quiescent. The net result is a legal landscape that could enable overreach and abuse by a president not only firmly committed to norm-breaking but with a history of demonizing minority populations.

Three executive powers in particular — to deploy financial sanctions, criminally prosecute certain forms of speech and advocacy, and detain people without trial — have been deepened in the past two decades.

We normally think of financial sanctions being levied against foreign entities, such as the Central Bank of Iran and Iranian officials. On Sept. 25, 2001, however, the administration of President George W. Bush created a new category of “Specially Designated Global Terrorists,” or SDGTs, subject to asset freezes and exile from the global financial system. Today, the list of SDGTs runs 1,359 pages.

While the designation has been applied to Hezbollah and various Iranian and Iraqi militias, it has also been used to target domestic groups. In October 2004, the Islamic American Relief Agency, based in Columbia, Mo., was designated an SDGT because the government determined it “related and connected” to a designated foreign organization, the Islamic African Relief Agency, based in Sudan. The Columbia organization countered that there was no evidence that it supported terrorism and denied a continuing relationship with the Sudanese entity. In a challenge to the freeze, the U.S. Court of Appeals for the D.C. Circuit upheld the government’s designation, accepting the argument that the two groups had a common “genesis and history” and had undertaken vaguely specified financial interactions with other affiliates of the Sudanese entity.

Important for today, the court stressed that, given the national security context, judges had to be “highly deferential” to the executive branch. As a result, whatever the truth of the allegations behind a designation, they are unlikely to be tested closely in court.

Designation as an SDGT has wide ramifications. “Transacting” with such an entity carries a 20-year criminal sentence. Such transactions can include providing “services,” a term that on its face extends to legal representation and advocacy for the group.

The First Amendment provides no protection here. Ruling on a similar “material support” statute in 2010, the Supreme Court held that the government could prosecute “any contribution” to a designated organization, including otherwise constitutionally protected speech. Indeed, the court noted that the plaintiffs in the case before them sought to provide “legal training and political advocacy” on behalf of designated groups — and it still found no barrier to the designation.

It is not hard to imagine President Trump, perhaps goaded by one of his trusted media sources — Fox News, the One America News Network — designating as terrorist groups domestic organizations advocating for Iranian American interests or taking the position that war against Iran would be a mistake. CAIR, the legal group advocating for detained Iranian Americans in Blaine, has long battled calls to have it blacklisted. It is frighteningly easy to contemplate other antiwar groups, such as the National Iranian American Council, facing the same threat (indeed, Fox has already tagged it as “Iranian-government tied”).

The repercussions of SDGT designation, in short, would not be limited to the entity itself. Thanks to the Supreme Court’s crabbed reading of the First Amendment, that designation could cast a paralyzing chill across civil society, leading lawyers to think twice before defending such a group and other civil society groups to give it a wide berth.

While the SDGT regime relies on criminal sanctions, the government has many other tools that could be wielded to directly target the liberty of Iranian Americans. Immigration law has been the administration’s go-to for detention authority, but it is unlikely to matter here. The 2017 travel ban already bars from entry most Iranians who lack U.S. citizenship or a green card. Although a waiver procedure formally exists, in practice it is nugatory. Even an ailing 85-year-old grandmother of Iranian origin is denied permission to visit her grandson, a congressional staffer.

What other legal authority might permit detention without trial of U.S. citizens or green-card holders of Iranian descent? Although the Trump administration has yet to provide a detailed legal justifications for the Soleimani strike, it is plausible to expect that an Authorization for Use of Military Force, or AUMF, enacted in 2002 will figure in its argument. National security adviser Robert C. O’Brien has already mentioned the 2002 AUMF in passing.

There have been two important AUMFs passed in the past two decades. The first was enacted in September 2001 in response to the 9/11 attacks and the second in 2002, in the run-up to the Gulf War, both vesting the president with power to use “necessary and appropriate” force to “defend U.S. national security.” Congress recently tried and failed to muster the votes to foreclose the application of the 2002 AUMF against Iran — a failure the administration will no doubt take as affirming extremely broad legal authority in the confrontation with that country.

Invoking the “necessary and appropriate” language of the two statutes, President George W. Bush’s administration detained one U.S. citizen and one noncitizen visitor, Jose Padilla and Ali al-Marri; both were seized in the United States and held in indefinite military custody without criminal trial. They were initially charged in the criminal justice system but were peremptorily hauled into a military brig from federal jail upon being labeled “enemy combatants.”

In both of these cases — widely viewed at the time as trial balloons by the government — a legal challenge to the detention was rejected in the lower federal courts. The government then moved the detainees from military custody to render the case moot before the Supreme Court could act. The result is that the only legal precedent on the books on AUMF detention authority didn’t stop the government seizing citizens and noncitizens alike in the United States.

How broad might this power run? In ruling on the travel ban in 2018, the Supreme Court was at pains to distance itself from the internment of Japanese Americans during World War II. But nothing in the opinions I have mentioned precludes the wholesale rather than retail use of AUMF detention power. Nor are our courts, newly stocked with Trump appointees, likely to raise more than token opposition.

As we wait to see what the Soleimani killing portends, it would be wise to keep one eye on the home front. The ground has been laid for tragedy. It would be foolish to imagine that the supposedly coequal branches of Congress or the courts will step in, either. After all, they gave their blessing to the current set of laws and policies. It doesn’t take a leap of imagination to suggest that, a decade hence, the Soleimani killing may be remembered as a catalyst for a suite of repressive measures against Iranian Americans.