A tense debate over whether Britain should rearm against Russia — bad news for anyone hoping the West is cooling down, and a sharp split over whether deterrence prevents wars or starts them.

• Rees-Mogg argues Britain must build up its military because Russia is already attacking the West through poisonings, cyber attacks, and probing undersea cables.
• Carlson counters that Britain is funding a war against Russia, so Russian hostility is cause and effect, not random aggression.
• Britain's combat-ready force is tiny, and the money for a buildup would have to come out of welfare spending.
• The two agree Britain's bigger threat comes from its own government — people arrested over social media posts and protest groups, and mass immigration it cannot control.
• They split hard on morality: Rees-Mogg defends Hiroshima as a just act that ended the war; Carlson says killing innocents is never justified.

Outlook: Britain looks set to push defense spending toward 3.5% of national income while the argument over whether that deters Russia or provokes it stays unresolved.