The growing threat to American satellites from Chinese and Russian anti-satellite weaponry was a key driver behind President Trump's directive creating a new space military force.

Trump on Tuesday signed Space Policy Directive-4 ordering creation of a new U.S. Space Force to be a separate service within the Air Force —the military leader for national security space operations.

"America must be fully equipped to defend our vital interests," Trump said in signing the directive. "Our adversaries are training forces and developing technology to undermine our security in space, and they're working very hard at that."

The action follows the creation a Space Command in December that will coordinate space activities for all military services.

Space is now an integral part of the American way of life and supports communications, finance, and transportation, among other services. Space systems also are vital for national security, providing intelligence, communications and precision navigation used in targeting weapons.

While the United States remains the world's leading space power, the directive warns that "adversaries are now advancing their space capabilities and actively developing ways to deny our use of space in a crisis or conflict."

The directive urges developing deterrence of foreign space aggression and protecting U.S. interests in the new warfighting domain.

The Space Force will be set up as the sixth military branch, similar to the status of the Marine Corps, as part of the Navy.

The force will organize, train and equipment military space forces to "ensure unfettered access to, and freedom to operate in, space, and to provide vital capabilities to joint and coalition forces in peacetime and across the spectrum of conflict," the directive says.

The new force must first be approved by Congress.

In addition to defending satellites and other space assets, the most significant statement in the directive is the requirement to prepare for space conflict. One of several missions of the Space Force will be "projecting military power in, from, and to space in support of our nation's interests," the directive says.

That language will permit the Space Force to develop and deploy space weaponry in space, air, sea and land.

Currently, the United States has no known space weapons. However, several missile defense capabilities could quickly be modified into ASAT systems. Past work on lasers also could provide a base for developing ASAT lasers. The Navy used a modified SM-3 anti-missile interceptor in 2008 to shoot down a falling intelligence satellite.

An intelligence report by the Pentagon's Joint Staff J-2 intelligence directorate warned in an alarming internal report in 2018 that China and Russia have built anti-satellite missiles, lasers and other weapons that in the near future will be able to damage or destroy all U.S. satellites in low earth orbit.

The report said "China and Russia will be capable of severely disrupting or destroying U.S. satellites in low Earth orbit" over the next several years. The ASAT attack capabilities could be in place as early as 2020.

Director of National Intelligence Dan Coats supported that view during an annual threat briefing for the Senate Intelligence Committee Jan. 29.

"We assess that China and Russia are training and equipping their military space forces and fielding new antisatellite (ASAT) weapons to hold U.S. and allied space services at risk, even as they push for international agreements on the non-weaponization of space," Coats said.

Chinese and Russian proposals to ban space weapons "do not cover multiple issues connected to the ASAT weapons they are developing and deploying, which has allowed them to pursue space warfare capabilities while maintaining the position that space must remain weapons free," Coats added.

The presidential directive followed release of a Defense Intelligence Agency study that revealed China will soon deploy a laser weapon capable of knocking out U.S. satellites in low-earth orbit in the next year.

The DIA concluded that China and Russia pose the most significant space warfare threats – despite both nations seeking arms control agreements limiting space weaponry.

Separately, the National Air and Space Intelligence Center (NASIC) in January stated in a report on space challenges that China and Russia are developing space warfare capabilities.

"Adversaries may jam global navigation and communications satellites used for command and control of naval, ground, and air forces, to include manned and unmanned vehicles," the report said.

"A number of foreign countries are believed to be testing on-orbit, space-based anti-satellite technologies and concepts," the report said. "China and Russia continue to conduct sophisticated on-orbit activities that may advance counterspace capabilities."

The NASIC report said American society is highly reliant on satellite services.

"What if GPS and other services were unreliable or unavailable?" the report noted. "Police, firefighters, and paramedics, who rely on satellite navigation, would be slow or unable to respond in an emergency. Live news from across the country or the other side of the planet would no longer be available. Long-distance telephone, satellite television, and internet would be unavailable. Retail stores and gas stations could not communicate with banks to complete transactions".

Russia has conducted several tests of an anti-satellite missile called the Nudol.

China, however, appears to be the most advanced space warfare state with numerous types of weaponry and capabilities. They include ground-based lasers that can blind or destroy orbiting satellites, several types of anti-satellite missiles capable of hitting satellites in both low and high orbit, small satellites that can maneuver to crush or grab satellites, and cyber attack capabilities designed to disrupt satellite operations.

"China is currently engaged in a large-scale ASAT weapons program that has profound implications for future U.S. military strategy in the Pacific," said Ian Easton of the Project 2049 Institute.

"China successfully tested and has reportedly deployed enough direct-ascent ASAT missiles to threaten the destruction of vital U.S. satellites in low-earth orbit," he adds. "China has also apparently tested and deployed at least one large, ground-based ASAT laser weapon for use on a number of targets in low-earth orbit, and is developing a submarine-based ASAT missile with which it could eventually target U.S. national security satellites in geosynchronous orbit."

Tidal McCoy, a former acting Air Force secretary, said he favors the new emphasis on military space but warned that the new entities must be "well led and well funded."

"Merely establishing the Space Command and Space Force does not guarantee that the U.S. will meet the challenge of Russia and China in space," said McCoy, chairman of the private Space Transportation Association. "Space strategy, programs, technology, funding, intelligence, and training are critical to our success to keep the peace in the High Frontier."

Retired Air Force Lt. Gen. Dave Deptula, a former Air Force intelligence chief, said he is opposed to the new force.

"The Space Force proposal is a resource question writ large: Too much mission, too few dollars," he said.

"Standing up a separate space bureaucracy amplifies the problem by driving more money to a headquarters function, not space operations."

Deptula said currently there are no space weapons that are fundamental to creating a new armed service.

"Constraints to fully-weaponized space capability must be debated and changed by Congress to allow the Air Force to mature space warfare theory and concepts of operation for war in, from, and through space—these are prerequisites for establishing a new armed service," he said.

The Pentagon's Defense Science Board in 2017 issued a report on the threats to military space systems and urged, in a classified report, developing a new strategy for space warfare.

The report stated that military superiority in space is "absolutely essential in achieving global awareness, information dominance on the battlefield, deterrence of potential conflict and superiority combat effectiveness of our forces."

The board also warned that "threats to space superiority have grown significantly."

To bolster space capabilities, the board urged greater investment and commitment to space defense and produces a strategy and implementation plan. It is not known if the plan includes creating a Space Force.