The top U.S. military officer said Wednesday that while the United States is still the world's most powerful fighting force, other countries are starting to close the gap.
Announcing the 2015 National Military Strategy, Joint Chiefs Chairman General Martin Dempsey said other nations are investing heavily in their military capabilities.
The general said that since the Pentagon published its last military strategy in 2011, global disorder has increased and some of the advantages the U.S. had over other nations have started to erode.
Dempsey said the U.S. military needs to be more agile, innovative and integrated, and it must remain globally engaged.
The 2015 strategy notes that Russia has "repeatedly demonstrated that it does not respect the sovereignty of its neighbors" and is willing to use force to achieve its goals. It says "Russia's military actions are undermining regional security directly and through proxy forces," a reference to its support for separatists in eastern Ukraine.
The strategy says Iran's nuclear program worries U.S. allies in the Mideast and that Iran actively sponsors terrorist groups in Iraq, Lebanon, Syria and Yemen.
It calls North Korea an "outlaw state" with atomic weapons and says it is building missiles capable of reaching the U.S.
But the strategy says China is in a "different class" and encourages the Chinese to "become a partner for greater international security."
It does say, however, that China could be a threat to the U.S. and that its actions in the South China Sea — where China has flaunted its military might in island disputes with its neighbors — are "worrisome."
The strategy says globalization and technology are letting people travel around the world in a way never seen before, and that makes a complex security situation even more complicated.
The Islamic State group in 2015 is not like al-Qaida in 2011, with a command-and-control unit giving orders. Dempsey called Islamic State "transregional" with other terrorist groups placing themselves under the Islamic State umbrella.
He said the U.S. is trying to build a network to combat the group — one that must be sustainable and endure.