Gregory Korte

USA TODAY

WASHINGTON — The post-9/11 state of national emergency — declared by President George W. Bush three days after the 2001 terrorist attacks — will continue through the end of the Obama presidency.

President Obama has extended Bush's Proclamation 7463 for the 16th consecutive year, giving him broad powers over the organization of the military for at least another year.

Among them: the ability to call up the national guard and deploy those troops overseas. As of last week, 16,345 guardsmen remain called up under the legal authority involved by that proclamation, the Pentagon said.

The emergency also gives the president — and his successor — the authority to "suspend the operation of any provision of law relating to the promotion, involuntary retirement, or separation of commissioned officers" of the armed forces. And he can appoint an unlimited number of new one- or two-star generals, waiving promotion requirements and legal limits on the number of officers.

Wednesday, GOP candidate Donald Trump suggested he would use his authority as president to replace top generals, saying he would seek the advice of generals on the Islamic State, but "they’d probably be different generals, to be honest with you."

Under the National Emergencies Act, national emergencies expire after a year, unless the president renews them by notifying Congress.

Obama did just that last week. "The terrorist threat that led to the declaration on September 14, 2001, of a national emergency continues," he said. "For this reason, I have determined that it is necessary to continue in after September 14, 2016, the national emergency with respect to the terrorist threat."

Congress is also required to meet every six months to consider whether to revoke each state of emergency. In 40 years of the National Emergencies Act, Congress has never done so — and only seriously threatened it once.

There are now 32 states of national emergency pending in the United States, with the oldest being a 1979 emergency declared by President Jimmy Carter to impose sanctions during the Iran hostage crisis. Most are used to impose economic sanctions — mostly as a formality, because Congress requires it under the International Emergency Economic Powers Act.

Special report: America's perpetual state of emergency

In his term in office, Obama has declared 13 new emergencies, continued 21 declared by his predecessors and revoked just two, which imposed sanctions on Liberia and Russia.

But Proclamation 7463 is unique among those national emergencies. Along with a use-of-military-force authorization by Congress signed by President Bush four days later, it gives the president the power to call up the national guard and to alter the size and shape of the military's top officers. It also gives him the power to hire and fire commissioned officers — even ordering them out of retirement if necessary.

As of 2014, there were 10 generals serving in such positions, but the Pentagon could not determine what that number is currently.