Europe’s heading into winter facing an unprecedented energy squeeze, and politicians are trying to figure out how to stop their citizens from freezing.

If the shortages worsen, European governments could resort to curbing sales of natural gas and power to other regions. An even more extreme scenario could see them halt flows to one another, triggering a political and economic crisis.

"If it gets very cold, even within Europe you will see countries say: ‘I have the gas inside my borders and I am going to pass an urgent safety measure that no one can export for the next two weeks,’” said Marco Alvera, chief executive officer of Italian energy-infrastructure company Snam SpA. "I have been threatened in several countries over the last 20 years. Political priority is to keep your constituency.”