Between World War I and World War II, U.S. military planners studied how warfare might change from the trenches to the high seas and to the skies.

Thank goodness. Although the Japanese attack on Pearl Harbor surprised the nation, it did not take long for the thinking that was done years earlier to be brought to bear. We were ready with a strategy and able to build submarines, aircraft carriers and bombers to defeat very capable German and Japanese forces on land, sea and in the air.

Today, our objective is deterrence, but our need to study and anticipate change in the nature of warfare is as urgent as it was in the interwar period. That’s where we are now with space, a domain that, until recently, was a benign  frontier defined by satellites and a future of daring exploration.

America is the best in the world at space, and our adversaries know it. They are developing and testing capabilities to deny us the use of space in crisis or war.

The Air Force is  responsible for 90 percent of America’s military space assets and we see clearly where American interests are threatened. We are dramatically increasing our space budget this year and we are developing concepts and capabilities to deter and defeat any adversary who threatens our ability to freely operate in space.

While most Americans use space every day, few are conscious of it. It’s  seamlessly woven into our lives. Air Force-operated GPS satellites give you the blue dot on your phone and provide the timing  for banking, communications, and the stock exchange. One recent study showed that the Global Positioning System’s value to the U.S. economy was about $70 billion per year.

We must continue to work with our allies to strengthen our collective self-defense in space, just as we have on Earth. And we must continue to study how our enemies might exploit vulnerabilities and how we will defeat them, just as military planners did before World War II.

In the coming years, our military will undertake a number of steps to ensure our vital space capabilities are resilient so that our potential adversaries  are deterred from attacking us. These steps include  reducing the time  to develop and to launch critical new satellites; creating warfighting tactics for  our troops to  train against satellite-jamming, laser attacks and other threats; and fielding defendable space systems and the capability to protect them.

The stakes are high and America’s leadership is aligned. Make no mistake, Russia and China are developing anti-satellite capabilities that could become operational in the next few years. Our new National Defense Strategy correctly recognizes the reemergence of great power competition with China and Russia as the principal priority for the Defense Department.

We must continue to work with our allies to strengthen our collective self-defense in space, just as we have on Earth. And we must continue to study   how our enemies might exploit vulnerabilities and how we will defeat them, just as military planners did before World War II.

There is much work to be done to ensure space continues to be open and accessible to the world and that our systems are secure from attack. It is an urgent national priority.