The U.S. military is quickly heading towards becoming a one-war-capable force instead of a two-war force, with being only "marginally able" to defend the nation due to lack of troops and weapons, according to a new report by The Heritage Foundation on Tuesday.

President Obama's latest national security strategy aims to size the armed forces in a manner that will allow four military branches to have sufficient troops, ships, tanks and aircraft to win a large war, while simultaneously acting to "deny the objectives of - or impose unacceptable costs on - another aggressor in another region," The Washington Times reported.

In other words, the military would be able to essentially fight two major conflicts at the same time, the Quadrennial Defense Review said.

However, the rapid dwindling of troops and weapons by the U.S. military makes it almost impossible for the Obama administration's strategy to work, according to Heritage's "2015 Index of U.S. Military Strength," both a scorecard and a research tool.

Simply put, the military cannot fight two wars at once.

"The U.S. military itself is aging. It's shrinking in size," said Dakota Wood, a Heritage analyst. "And it's quickly becoming problematic in terms of being able to address more than one major conflict."

"The U.S. military is rapidly approaching a one-war-capable force," said Wood, a former Marine Corps officer and strategic planner. "So [it is] able to handle a major war and then having just a bit of residual capability to handle other minor crises that might pop up. ... But it is a far cry from being a two-war force."

"The consistent decline in funding and the consequent shrinking of the force are putting it under significant pressure," the report concluded. "The cumulative effect of such factors has resulted in a U.S. military that is marginally able to meet the demands of defending America's vital national interests."

According to the "2015 Index of U.S. Military Strength," the Army is shrinking from 570,000 soldiers to 440,000 or lower, while the Navy, which is failing to achieve a 300-ship force, has been graded as only "marginal" in military power. The Air Force's fleet of fighters and long-range bombers is judged to be "strong."

Due to automatic budget cuts known as "sequestration," the Army might only have 33 brigade combat teams, far short of the 50 brigades that are required for two wars.

The Air Force "would say we are dangerously close to no longer being able to guarantee the air dominance that we could guarantee in Kuwait," Rep. J. Randy Forbes, Virginia Republican, said, referring to the 1991 Desert Storm operation over Iraq.

"If you listen to the Army, they will give testimony they can no longer guarantee. You talk about two wars - they testified they can't guarantee that we could win one war," Forbes said. "The Navy will tell you if we get to 260 ships, we cease to be a superpower; we become a regional power."

Meanwhile, the last three Pentagon's base budgets under Obama have decreased from $527 billion in 2010 to about $496 billion. But for 2016, the president has asked for an increase of $534 billion.