In a move by Congress that assistant teaching professor Dan Urman called “remarkable,” in part because Congress rarely agrees on anything, the legislative branch overwhelming overrode President Barack Obama’s veto of the so-called 9/11 lawsuit bill.

As a result, U.S. citizens will now have the power to sue foreign nations that played a role in terrorist attacks resulting in American deaths. Urman, director of the minor in Law and Public Policy, explains what the next steps are and how this new law could impact U.S. relations abroad.

What are some of the key aspects of this bill?

The bill, entitled “Justice Against Sponsors of Terrorism Act” (JASTA), creates an exception to the basic international law concept of sovereign immunity, which is that countries are traditionally shielded from individual lawsuits by citizens of another country. Now, it is much easier for American individuals to sue foreign countries in federal court if the country played any role in terrorist attacks leading to American deaths, including but not limited to 9/11.

The bill amends a 1976 law that had granted countries immunity from lawsuits in American courts unless the country was on the U.S. Department of State’s annual “State Sponsors of Terrorism” list. (There are a few other rare exceptions to immunity.) The current list of state sponsors includes Iran, Sudan, and Syria.

JASTA does not entirely strip the executive branch of its traditional authority over foreign affairs and diplomacy, however. The law permits the United States attorney general to join a lawsuit and have a judge block any ruling or settlement of claims. The judge can stop the proceedings if the United States says it “is engaged in good faith discussions” with the country to resolve the claims.

Now that Congress has made its feelings known, what can we expect to happen next?

First, Congress may amend the bill because of concerns about retaliatory actions by U.S. allies and adversaries. Over the past week, members of Congress who voted for the bill and veto override openly worried about U.S. officials being subjected to private lawsuits in foreign courts. One option involves a narrowing of the bill to only include lawsuits related to 9/11, but I doubt that will happen before Election Day.

Second, people affected by terrorism will begin filing lawsuits against nations they believe played a role in the attacks. Judges will have to clarify the meaning of the bill; as it currently stands, the law’s vague wording means that individuals could sue any country whose actions relate to terrorism that caused property loss or personal injury, and this is a longer list of nations than the bill may have had in mind. The families who lost loved ones on 9/11 will move forward with their lawsuits against the Saudi government, and the Obama administration will ask the judges to stop the proceedings. This might cause the Saudi government to set up a victims’ compensation fund or quietly settle the lawsuits.

What are some consequences that could arise from this bill?

By reducing the amount of immunity it provides to foreign nations in American courts, JASTA invites other countries to reduce American immunity abroad. The United States has, by a longshot, the most personnel and assets abroad in the world. This could lead our diplomatic and military officials to be brought into many nations’ courtrooms, even if the charges lack merit. President Obama said as much in his veto statement last week: “Reciprocity plays a substantial role in foreign relations, and numerous other countries already have laws that allow for the adjustment of a foreign state’s immunities based on the treatment their governments receive in the courts of the other state.”

Countries can and always have claimed legal authority over individuals and countries beyond their borders—referred to as “extraterritorial jurisdiction”—but it rarely goes anywhere. After all, nations need to enforce any judgments. This brings up a host of diplomatic and military issues, and most countries resolve such disputes through international bodies, not military force. This is relatively uncharted territory, because it represents a tension between international diplomacy, international relations, and legal liability.

Outside of America’s sworn enemies, other nations do not permit their citizens to sue entire countries for harm caused by terrorism. The most significant cases involve commercial law and trade, but we should expect nations to pass their own version of JASTA.