Will the National Defense Authorization Act get policies and spending priorities right? Congress is expected to “drop” (introduce) the bill soon; if it gets things wrong, the nation could pay a very high price

Amid all the Obama administration’s scandals, we shouldn’t lose sight of national security matters. Just last month, we were rocked by the Boston marathon bombings and North Korean promises of turning US cities into a “sea of fire.” Similar (and other) threats haven’t gone away just because they aren’t making headlines.

We live in a dangerous world. China’s rise, Russia’s resurgence, troubles from Tehran, cyber space challenges, Pyongyang’s perfidies, Arab Spring anxieties, Syrian spillover, international Islamist militancy (and others) are problems we’ll have to face.

Indeed, the latest version of the defense bill may be more important than any in the recent past as the budget-bending “sequester” hits the Pentagon, trickling down through our armed forces.

This next Pentagon spending bill will define our expectations for America’s role in the world. It will be distributed, dissected and digested far beyond the halls of Congress and K Street by foreign friends and foes alike — from Tokyo to Tehran and Brussels to Beijing.

In general, the bill’s final version must maintain a high-tech, modern US military capable of projecting power across the globe to meet our security commitments to allies and friends and protect and advance other American interests.

There isn’t space here to discuss everything that should go into the bill, but here are five key themes:

Maintain robust conventional force structure: This means having the planes (40-plus fighter squadrons), ships (300-plus) and troops (200,000 Marines and 600,000 soldiers), etc. to meet the various (likely) security challenges in the coming years. We must be both fierce and flexible. (Team Obama’s current budget proposal underfunds defense, jeopardizing its heralded Pacific “pivot” strategy.)

Modernize/expand strategic offense and defense: With North Korea in the nuclear club, Iran on the threshold — and Russia and China modernizing — it’s common sense to keep our own nuclear forces in good shape. We should also expand missile defenses to keep ballistic missiles at bay. (Again, the Obama team is reluctant to spend enough on these fronts.) And don’t forget cyber and space dominance, both cutting-edge “battlespaces.”

Preserve global reach: Beyond ships and transport aircraft to move bullets and beans, you need bases and places for transit, resupply and hosting US forces if needed. For example, calls for closing bases in Europe is a bad idea since the continent is a gateway to hotspots in the Middle East, Africa and parts of Asia.

Support friends and allies: As Winston Churchill said: “There is only one thing worse than fighting with allies and that is fighting without them.” To this end, we should sell F-16 fighters to Taiwan, which needs them to keep peace across the Taiwan Strait with China, an important American interest.

Prepare for emerging threats: Since a tank — or any defense system — can’t be built overnight, we need to look into the security crystal ball to make sure we don’t end up fighting the last war. For example, we’ve spent years engaged in counterinsurgency battles — but will we be equipped for confronting a major power such as China? Being ready should be based on rock solid intelligence estimates, another important spending priority.

In the end, if you don’t seek to shape the international security environment, you guarantee that you’ll be shaped by it. It’s a choice. But remember, dissuasion, deterrence and deadly force (if required) are critical elements of our defense posture.

The hard-knocks, concrete playground of international politics is full of competition, surprise and possible pain. It’s a come-as-you-are affair — and the “wouldas” and “shouldas” spoken of in the aftermath of crisis or conflict just don’t count.

-Peter Brookes is a Heritage Foundation senior fellow and a former deputy assistant secretary of defense.