New Delhi, Jan. 25 -- President Donald Trump and his Ukrainian counterpart Volodymyr Zelensky met in Davos, Switzerland on Thursday to discuss an end to Russia's war. No concrete plans were drawn up, but both leaders emerged optimistic about their progress. Attention should now turn to what peace might bring-not just for security, but for business. When the fighting stops, the most promising opportunities for U.S. companies won't be in Russia, but in Ukraine.

At first glance, Russia might seem the more attractive market. It has 140 million people, a $2.2 trillion economy, and vast natural resources. But even after hostilities subside, political and commercial risks will remain high and the range of investment opportunities therefore narr...