OPEC’s meeting this week takes place against a gloomy background: A global economic meltdown has caused oil prices to fall even as Russia’s war against Ukraine has made supplies more uncertain than ever. An expected production cut could combine with other factors to send prices sharply higher. In fact, it isn’t hard to see how oil could climb back to $100 even as the economy weakens. Oil prices rose on Monday, with Brent crude BRN00 –0.47% climbing to nearly $89 per barrel. Shares of oil companies also rose, with the SPDR S&P Oil & Gas Exploration & Production XOP +5.24%...