A recent Gallup poll shows that Americans see the U.S. as the world’s top military power now but doubt whether this will be true in 20 years. Only about a third of Americans believe the U.S. will still be ranked first militarily in 2029.

Americans are intuitively smart, and they have taken note of a disturbing trend occurring outside the headlines: investment in military modernization is declining during a time of rapid military buildups abroad. They are right to be concerned.

In recent months, Heritage has drawn attention to several areas where the U.S. Armed Forces are at risk of losing vital capabilities the nation has enjoyed for the last half-century. Continued cuts in future defense investments proposed in President Obama’s 2010 and now 2011 budgets are putting long-held U.S. military advantages in jeopardy. These cuts are coming at a time when the U.S. military is already experiencing shrinking margins of technological superiority relative to the rest of the world.

Evidence of the potential decline can be found in two examples, including the submarine force and tactical fighter aircraft fleet. For one thing, the U.S. submarine fleet is projected to bottom out at 41 boats by 2028 (PDF) — far fewer than the Navy’s stated requirement. At the same time, China is developing sophisticated undersea warfare capabilities and investing substantial sums in developing and acquiring new submarines and underwater mines that could heavily damage U.S. fleets in a naval confrontation.

The second example: In just over a decade, the Air Force fighter gap will grow to over 800 planes (PDF) if current plans progress without congressional intervention. While U.S. fighter fleet requirements continue to go unmet, Russia and China are developing highly modern fighters, such as the futuristic fifth-generation Sukhoi T-50 unveiled by Russia in January. Equally worrisome, the U.S. is consolidating now toward having only one fighter production line in operation. Meanwhile, Russia and China together have 12 fighter and bomber lines open today.
A shifting military balance does not bode well for American security or for global stability. Declining defense capabilities limit the foreign-policy options of current and future administrations and jeopardize security commitments while undermining national interests.

To prevent the U.S. from losing its rank as an unmatched military power, Congress must prioritize military modernization. This will require raising the defense budget topline and preventing runaway entitlement spending from encroaching upon the defense budget. It will also require constraining the growth in military health-care spending and other overhead costs that are chipping away at investment in modern equipment.

Cross-Posted on National Review’s “The Corner” blog.