Military power depends on many factors – nukes, size and budget, but also training, leadership, morale and technology, including the ability to project power to other locations. In a world without any overall authority, nation-states need military power to ensure their safety.
However, superior military power does not guarantee victory. France could not win in Algeria or Vietnam. The USSR could not win in Afghanistan. The U.S. could not win in Vietnam, Iraq and Afghanistan. In all these cases, it was because they faced guerilla war and terrorism, forms of asymmetric warfare. In fact, the only recent wars the major powers have lost have been due to asymmetric warfare.
In 1995, an undetected Chinese sub popped up near a big U.S. Navy exercise, as a reminder that they could have fired torpedoes into the carriers and other ships. As relatively cheap missiles and subs have become more capable, even advanced ships, planes and tanks are more vulnerable. China now has enough subs and anti-ship and anti-aircraft missiles so that strategists say that a U.S. naval force would have to stay about 1,000 miles away if there were a conflict over Taiwan. That is too far for U.S. planes to reach.
(The U.S. lost 18 out of 18 war game simulations in this situation.) So, China is spending millions to asymmetrically neutralize multi-billion dollar American aircraft carrier groups. Furthermore, in 2007 the Chinese destroyed one of their own satellites, to remind the U.S. that they could do the same to the satellites that America depends on for its military communications. Asymmetric warfare again.
In addition, the Russians have developed jamming techniques against GPS and other hi-tech communications and data. The result is that U.S. troops now have to learn to train without outside contact, just in case. Furthermore, dozens of countries now have cheap Chinese drones such as those Iran used in the September 2019 strike against oil facilities in Saudi Arabia and those currently being used in Libya.
Everyone has learned the lessons of the two Iraq wars – the futility of directly opposing U.S. forces, and the relative success of asymmetric war such as terrorism, guerrilla war and propaganda. So Iraqi insurgents use cell phones to set off roadside bombs made out of fertilizer and diesel fuel, pay unemployed Iraqis to fire one shot to kill one American, and disable high-tech U.S. tanks with cheap rocket-propelled grenades. Terrorist groups Hamas and Hizbollah fire homemade rockets against Israel’s multi-million-dollar computerized Iron Dome anti-missile system. The Vietnamese learned to ruin expensive U.S. “people sniffers” dropped by airplanes into the jungle by urinating on them, and dug pits with excrement-covered bamboo “punji stakes” for U.S. soldiers to fall into. All this was anticipated in Kipling’s 1886 poem “Arithmetic on the Frontier,” which described how a poor, unschooled tribesman could use his homemade rifle to kill an expensively-educated British officer.
Another problem for big countries is that military power does not necessarily bring obedience in other dimensions. The U.S. could not persuade the U.N. Security Council to authorize the use of force in the 2003 Iraq war, enact sanctions against Sudan for the genocide in Darfur or intervene in the current civil war in Syria.