Here are five reasons the world’s largest economies are watching what happens in Ukraine. (Courtesy: KCRA.com/CNNMoney). *An important tie: Ukraine is an important tie between Russia and the rest of Europe. Russia supplies about 25 percent of Europe’s gas needs, and half of that is pumped via pipelines running through Ukraine. Moscow has cut off that flow in past disputes with Kiev and a disruption could push up energy prices for businesses and households. *Sanctions on Russia: One prospect on the table would be the unusual circumstance of a top-10 global economy placing sanctions on another. But Secretary of State John Kerry said Sunday the US is “absolutely” willing to consider sanctions against Russia. President Obama, he added, “is currently considering all options”. *European and world trade could be impacted: The impact could be felt beyond Europe if the world’s supply of grain is impacted. Ukraine is one of the world’s top exporters of corn and wheat, and prices could rise even on concern those exports could halt. *Ukraine govt in debt: Ukrraine owes $13 billion in debt this year and $16 billion comes due before the end of 2015. Without help, the country appears to be headed for default. It’s not clear who would supply the needed economic assistance, especially after the ouster of key Russian-aligned officials prompted Moscow to freeze a $15-billion bailout and there is no comparable alternative in sight. *Ukraine isn’t the only fragile emerging market: Ukraine’s instability comes at a difficult time for emerging markets worldwide, which are seeing growth slow as the Federal Reserve eases its economic stimulus. The situation in Ukraine could lead investors to reassess the risks of other emerging markets slowing economic growth.