Russian President Vladimir Putin says he has deployed troops into Crimea to protect those whose affinity and culture is Russian.
The United States sees Putin's actions as an attempt to annex the Ukraine peninsula as an aggressive military move and a violation of international law.
The turmoil has triggered violent protests, killing at least 77 people and injuring hundreds more.
Crimean lawmakers recently agreed to secede from Ukraine to unite with Russia; the matter will be put to a public vote on March 16.
The volatile situation has some local people with Ukrainian connections concerned.
Alexander Prociuk is president of the Organization for the Rebirth of Ukraine, owners of Ukrainian Homestead, Lehighton.
"Our contacts tell us that the people of Ukraine very worried about Mr. Putin's plans for Ukraine and how much support the west will give Ukraine.
"I know one person who was severely beaten at the Maidan (Independence Square) where unarmed civilians were shot by the storm troopers and thugs. Fortunately he was moved to Liviv, in western Ukraine, to recuperate at a hospital there," Prociuk said.
"What Putin is doing is totally illegal, but it is nothing new for him; he gets away with it as in Georgia, human rights in Russia, and every agreement he has signed with Ukraine. He is violating the 1994 agreement when Ukraine gave up its nuclear weapons. Included in this agreement were guarantees by Russia, England and the United States to honor Ukraine's borders.
"He lies about everything he is doing in Ukraine. I am not at all surprised at what this KGB agent does. He wants to rebuild the Soviet Union, and he cannot do this without Ukraine," he said.
Prociuk said Putin's actions are not the wishes of the Russian people.
"He pretends to speak for so-called Russians in Ukraine, while in reality these are Russian-speaking Ukrainians who voted in 1991 for Ukrainian Independence. I am very worried about family and friends. Ukraine has suffered, and many lives have been lost at the hands of Russian leaders like Putin," Prociuk said.
"I feel Putin will push ahead to get all he can get until the international community stops him. He is using the old Russian principle of taking two steps forward, and if caught, go back one step. Meanwhile, he is still one step ahead.
"The international community must use its power to financially stop him," Prociuk said.
"And it has to make Europe and Ukraine energy-independent of Russia. Admit Ukraine and the former countries of the Soviet Union into NATO, and make them partners of the west and promote democracy. Also, stop Putin's interference with the internal matters of these countries."
George Dydynsky of Beltzville, whose parents came to the United States from Ukraine in 1950 and 1951, is well-versed in Ukrainian and Russian history, and is following the situation with keen interest. He has family and friends in Ukraine, and has been in touch with people in Ukraine and in Moscow.
"I'm seeing a palpable optimism in Ukraine that this is going to end positively, that Putin is just trying to save face. But you never know," he said.
"Ukrainians as a whole, including myself, are grateful that the administration of the United States is trying to put great economic pressure on Russia, including the confiscation of ill-gotten gains by Ukrainians such as the (former) president, and of those Russians behind this mess," he said.
The well-being of family and friends is never far from his mind.
"I am concerned. War is always a possibility, which rational people in Russia do not want. But the politicians behind Putin seem to be encouraging (it)," he said. "It's a very, very complex issue. Your average person is scared over there."
Dydynsky disputes Putin's contention that Russian-speaking people in Crimea need protection, calling the argument ludicrous.
"Every Ukrainian speaks Russian," he said. "Russia has about as much claim to Crimea as does the United States."
Dydynsky believes Putin was behind the sniper shooting on protesters and police at the Maidan.
"People my age were killed in the Maidan," he said. "Who gave the order to start shooting?"