Three worsening simultaneous crises — Hong Kong, Kashmir and Israel-Iran — could trigger general conflagrations. Xi Jinping readies paramilitary police to crush Hong Kong democracy protests. India’s Hindu nationalist regime uses its military to crush Muslim opposition in Kashmir. Israel bombs Iranian-related targets in Syria, Iraq and Lebanon in a “shadow war.”

Beijing, Delhi and Jerusalem call their adversaries terrorists. The mistreatment of civilians creates hatred, respectively, in Taiwan, Pakistan and throughout the Muslim world. The three crises are remnants of border and governance problems the British left unresolved when they left their colonies in China, India and Palestine.

To retain power, Xi cannot back down but must subdue Hong Kong before the big 70th anniversary celebration of the proclamation of Communist China October 1. People’s Armed Police mass in adjacent Shenzhen, ready to coerce Hong Kongers into obedience. Brutality there could persuade Taipei’s independence-minded government to abandon caution and declare Taiwan a separate country, something most Taiwanese want. Beijing swears that would trigger its long-threatened cross-strait invasion.

The U.S. is not formally committed to defend Taiwan but could be drawn into war. Beijing, hyping nationalism, charges the U.S. with fomenting Hong Kong protests and denounces U.S. arms sales to Taiwan. By taking Taiwan, China would be better positioned to assert control over the contested Diaoyu/Senkaku islands just northeast of Taiwan. Chinese boats already ram Japanese coast guard vessels there. Japan is a U.S. ally.

Since independence from Britain in 1947, India and Pakistan have fought four wars, three over Muslim-majority Kashmir, now under Indian military occupation. Phones and Internet are cut off, and food and medicine are getting short. Both countries have nuclear weapons, which may deter open — but not guerrilla — war. Once enraged, however, they could escalate up to and including nuclear exchanges.

The U.S. is now negotiating a fig leaf to leave Afghanistan to the Taliban, whom Pakistan supports and India opposes. Small conflict easily escalates into irregular, then regular, warfare. Chaos on the Subcontinent favors the Taliban. Would the U.S. withdraw from Afghanistan, as Trump has ordered, or recommit?

Palestinians in Gaza and the West Bank and Iran-client Hezbollah in Lebanon rage against Israel. Iran uses Hezbollah fighters in Syria. An Israel-Hezbollah clash in the Golan could unleash thousands of newly upgraded Hezbollah rockets on Israel, which would not forbear. An Israel-Iran war and Saudi-Iran war would follow. Should we stay out? Could we?

One of my favorite writers on war is Australian economic historian Geoffrey Blainey, who in 1973 described a “world war” as several middle-sized conflicts linked together by opportunism. One war alters leaders’ power calculus, suddenly presenting them with hopes or fears over power and territory. The initial war makes other nations reevaluate their strategic situation, something that may be under way now.

In 1914, Austria-Hungary’s attack to punish Serbia encouraged both the Kaiser and Tsar to think: “Now we can become Europe’s most powerful country.” They raced to mobilize, each sure they would quickly win. France longed to get back Alsace-Lorraine, lost in 1871. Britain, initially aloof, feared Germany taking Belgium. Even Japan saw its chance to grab Germany’s Asian colonies. The initial little Austria-Serbian war metastasized.

What seemed unimportant and stable can become an urgent national interest in days. Example: In 1950, after careful consideration, Washington designated Korea as outside U.S. interests in Asia. The North’s invasion of the South in June illuminated in a lightning flash that this endangered Japan and other American positions in East Asia. Suddenly, the Korean War had to be fought.

While the three hot spots may flare simultaneously, other problem areas may not. North Korea’s young Kim is winning almost effortlessly. He builds new rockets and submarines unopposed while stringing along the U.S. president and Seoul quarrels with Tokyo. No wonder he is smiling. Putin would not gain by enlarging his invasion of Ukraine; all of Europe would turn against Russia.

As usual, Latin American armies are mostly for internal purposes (i.e., crushing rebellion), but Colombia and Brazil wish no more millions fleeing collapsing Venezuela. Russia supports Venezuela with loans and security personnel. The next U.S. president may not tolerate Putin’s intrusion in our hemisphere.

Africa’s wars are also mostly internal, but the fall of Gaddafi in Libya illustrates international linkage. During the ensuing chaos, Al Qaeda fighters seized Libyan arms depots. A CIA team attempted to stop them in Benghazi, where four Americans, including the ambassador, were killed in 2012. Al Qaeda sent truckloads of small arms southward for its affiliated Boko Haram in Nigeria and nearby countries, giving the region a major terrorist problem. Five U.S. special forces were killed in a firefight in Niger in 2017.

One conflict sparks others. Wise and responsible U.S. leadership could dampen conflicts. With America passive, little stops them from growing.