WAR
Russia, China, and the US try to maintain their spheres of military, political, economic, and cultural influence. It is a form of colonialism and empire. They often invade, overthrow, declare war, impose sanctions, or bribe countries in order to control them. They try to control their neighboring countries. Russia has done this in Ukraine, and earlier as the USSR, did similar things in Hungary, Poland, and Czechoslovakia. Saudi Arabia did it in Yemen. Britain has done this in Iran. China has done this in Taiwan, Tibet, and Nepal. India does this in Kashmir. Israel does this in Lebanon, Egypt, the West Bank, the Gaza Strip, and Iran. The US has done this in the Philippines, Hawaii, Vietnam, Chile, Guatemala, Honduras, El Salvador, Nicaragua, Iraq, Afghanistan, Libya, and Egypt. Sometimes it is to get the natural resources cheaply ( oil, uranium, gold, silver, lithium, cobalt, tea, opium, drugs). Sometimes it is for being able to sell weapons, cigarettes, opium, heroin, cocaine, or tea. Sometimes it is to get access to oil or to prevent other countries ( Iraq, Iran) from producing and selling oil, as competitors to western oil companies. Also, the US did not want the sale of oil to no longer be in US dollars (Iraq).
Weapons companies hire public relations companies to drum up the fear of other countries, so the weapons companies can get gigantic profits from weapons contracts. Weapons companies dominate the media and the government, pushing countries into war. We need a military and weapons companies, but they should not dominate our country. We can ask banks, mutual funds, and pension funds to divest from weapons cos. We can push politicians to refuse campaign money from weapons cos. We need campaign finance reform.
Modern wars mostly kill civilians. The US and Russia have dropped most of the treaties that limited the number, location, and deployment of nuclear bombs, missiles that can carry nuclear warheads, and nuclear armed submarines. Both the US and Russia are demonizing each other over the Ukraine war. They are both moving more nuclear capable missiles and ships nearer to the borders of Russia and of NATO. The risk of a nuclear war is increasing. And a nuclear war could easily thru the "fog of war" spin out of control into a "use it or lose it" situation with little time for safeguards against starting a nuclear Armageddon. Both countries are making "first strike weapons" , and military and political leaders are saying that they could win a nuclear war, by wiping out most of the opponent's missiles and subs. But even using a few nuclear weapons would cause so much dust to enter the atmosphere that most land-based plant life would die out from too little sunlight. So most people and land based animals would die out over several years of little light and no plant life.