The United States armed forces remain the most powerful military in the world trailed by Russia, China, India, and France, respectively, reveals the latest Global Firepower (GFP) index, which ranks 133 countries annually.

According to the GFP assessment, which echoes the most recent annual Jane’s Defence Budgets Report authored by prominent research firm IHS Markit, China and Russia together outrank their American rival.

However, the index also suggests that the military capabilities of allies the U.S., India, and France exceed that of China and Russia.

Facing a threat from nuclear-armed allies China and Pakistan, India has stepped up its game, joining the top five biggest military spenders in 2016 and remaining there the following year, reveals the most recent analysis of the world’s defense budgets by IHS Markit.

The top five military budgets include that of the U.S., China, India, Russia, and the United Kingdom, from most to least spender.

Although the United Kingdom spent more money on its military then France (8th largest budget), GFP gauged the French armed forces to be slightly stronger than the U.K.

Military spending is just one factor used by the GFP index to judge the capabilities of a nation’s military.

The Global Firepower index for 2017 relies on more than 50 such factors — including the range of weapons in the arsenal, available manpower, as well as resources and local industry — to produce its rankings of the most effective armed forces in the world.

“Our formula allows smaller, though more technologically-advanced, nations to compete with larger, lesser-developed ones. Modifiers (in the form of bonuses and penalties) are added to further refine the list,” notes Global Firepower in a press release about its 2017 rankings.

The military assessments come amid a rivalry between the United States and two of the nations ranked by GFP to be among the top five in the world — China and Russia.

U.S. military officials have repeatedly identified China and Russia as America’s top rivals, recently noting that Beijing’s military buildup has allowed the People’s Liberation Army (PLA) to challenge United States dominance in some regions.

Russian President Vladimir Putin has claimed that the U.S. and its NATO partners cannot intercept a new range of Kremlin nuclear weapons.

Putin boasted in a state of the nation address on Thursday of various Russian weapons that he alleged are unparalleled in strength and capable of rendering any NATO missile defense system “useless.”

According to the GFP index, America’s available manpower stands at about 45 percent of the population, but less than 40 percent is fit for service.

Meanwhile, there is a total about 2.4 million service members, including an estimated 1.4 million in active duty.

The United States owns 13,762 aircraft, 5,884 tanks, 1,331 rockets, and 415 naval assets.

In 2017, the U.S. defense budget stood at about $590 billion with American President Donald Trump requesting raises in subsequent years.

GFP gauged America’s “purchasing power parity” to stand at about $18.6 trillion, while the United States holds a similar amount of external debt — $17.9 trillion.