Russia’s oil-and-gas budget suffered a painful blow in 2025. Revenues from the sector fell 24% to 8.48 trillion roubles, the weakest showing since 2020. That matters because oil and gas still bankroll roughly a quarter of the federal budget, and that budget is being chewed up by defense and security spending at a pace hard to ignore. This is not because Russia pumped less crude. Oil prices fell more than 18% last year. That is the sharpest annual drop since the pandemic crash. On top of that, the rouble strengthened—bad timing. When…