Russian President Vladimir Putin¡¯s endgame in Ukraine remains unclear.

But his war there does seem to be sending one clear message: if you have nukes, nobody messes with you. The security risks this poses cannot be overestimated.

Just days after launching his invasion of Ukraine, Putin announced that he had placed Russia¡¯s nuclear forces on ¡°high alert¡± ¡ª a clear warning to the West not to intervene militarily on Ukraine¡¯s behalf. And it seems to have worked. Despite Russia¡¯s relentless bombardment, including of civilian areas, the United States has flatly refused Ukrainian President Volodymyr Zelensky¡¯s repeated requests for a NATO-enforced no-fly zone.