Attack on the United States

In May 2020, Donald John Trump stated that the United States had been attacked, and it was an attack worse than Pearl Harbor (which caused the US to enter World War II).

People are free to agree or disagree with that statement. The fact remains that the United States President publicly declared that the United States had been attacked in a manner worse than Pearl Harbor.

Two months prior to that statement, on March 13, 2020, Trump issued Proclamation 9994 declaring a national emergency due to the Coronavirus.

Recall what is necessary for the US President to engage the military in hostilities without a declaration of war from Congress:
(c) Presidential executive power as Commander-in-Chief; limitation
The constitutional powers of the President as Commander-in-Chief to introduce United States Armed Forces into hostilities, or into situations where imminent involvement in hostilities is clearly indicated by the circumstances, are exercised only pursuant to (1) a declaration of war, (2) specific statutory authorization, or (3) a national emergency created by attack upon the United States, its territories or possessions, or its armed forces.

Trump stated that Coronavirus was an attack on the US and declared a national emergency. He was then legally able to engage the military in hostilities, but did he?

Five days after declaring a national emergency, Trump referred to himself as a wartime president.

Later that month, on March 27, 2020, Trump issued EO-13912 to activate the Ready Reserve of the military. In the Executive Order, he referenced the National Emergencies Act, and Proclamation 9994 of March 13, 2020 (Declaring a National Emergency Concerning the Novel Coronavirus Disease (COVID-19) Outbreak).

The following month on April 30, 2020, Trump issued EO-13919 ordering the Selected Reserve to active duty

The War Powers Resolution states the President can engage the military in hostilities in the event of a national emergency created by attack upon the United States.

Trump stated that Coronavirus was an attack on the US, declared a national emergency, then activated the Ready Reserve and Selected Reserve to active duty.

Once the United States Armed Forces are engaged in hostilities, the Law of War applies. Traditionally, the law of war has been described as the only “authoritative rules of action between hostile armies,” or as superseding ordinary law in the actual theater of military operations.