This was written by Ukraine's National Security and Defense Council Secretary Oleksandr Turchynov in his opinion for The Washington Post.
"It was a temporary partnership of necessity in the face of a common enemy. As soon as Nazi Germany was defeated, the reality of Stalin's intentions became clear. Promises to hold free elections in the countries under Soviet occupation were broken, and the West spent the next 40 years trying to contain the threat the Soviet Union posed.
"This needs to be kept in mind as we contemplate events in Syria. In the aftermath of the horrific terrorist attacks in Paris and the bombing of a Russian plane over the Sinai, it is understandable that Western governments should want to form the broadest possible international coalition, including with Russia, to defeat those responsible. But shared grief is not the same as shared interests. Cooperation with Russia in the fight against the Islamic State needs to be carefully weighed against several bigger foreign policy issues.
"The areas where Russia's interests in Syria conflict with those of the West remain at least as significant as those where they overlap. Whereas the West's priority is destroying the Islamic State, Russia's primary aim is to keep the Bashar al-Assad regime in power. So far, a large majority of Russian airstrikes in Syria have been directed against non-Islamic State targets, including moderate groups such as the Western-backed Free Syrian Army that are helping fight the terrorist group on the ground. These strikes have also exacerbated the flow of Syrian refugees toward Europe.
"Russian President Vladimir Putin has direct interests in Syria as a regional ally, a market for Russian military exports and a base for the Russian navy's Mediterranean fleet. But his approach is influenced by wider considerations, one of which is to prevent another authoritarian regime from succumbing to the demands of its people. As we well know in Ukraine, Putin is determined to resist the tide of global democratic change and willing to use violence against other countries to stop it. He sees freedom as a threat to his own hold on power and an indication of advancing Western influence. Russian policy in Syria is framed by an attitude of strategic hostility toward the West and its values.
"While the Kremlin pretends to be fighting terrorism in Syria, Russia itself merits designation as a state sponsor of terrorism. Its aggression against Ukraine has cost more than 8,000 lives, including the indiscriminate shelling of civilian areas and the murder of political opponents carried out by its special forces and Russian-sponsored terrorists. It was a Russian-supplied Buk missile that reportedly shot down Malaysia Airlines Flight 17 in July of last year, resulting in the loss of 298 innocent lives. More than 1.5 million people in Ukraine have been internally displaced as a result of illegal Russian aggression. The Russian state has shown itself willing to carry out the assassination of regime critics, both at home and abroad, using terrorist methods.
"Yet none of this will prevent Russia from trying to extract advantage from the war in Syria. Putin is a master of tactical opportunism, and in the past two weeks Russian jets in Syria have been dropping bombs inscribed with the message "For Paris" in a gesture of apparent solidarity. Positioned as a friend of the West in its fight against terrorism, Putin hopes to secure the relationship he has always wanted - one that sets aside international law and the rights of smaller nations in favor of great-power dealmaking and the principle that might is right.
"Russia has already invoked the grand alliance against Hitler as a precedent for fighting the Islamic State. Be in no doubt that it will also demand a new Yalta as the price of cooperation now. In his recent speech to the United Nations, Putin praised the post-World War II agreement that began the division of Europe by recognizing the territorial gains Stalin achieved under the Nazi-Soviet pact. The town of Yalta, of course, now lies in Russian-occupied Crimea as a poignant reminder that the past lives with us. All Putin needs is for the West to drop sanctions and accept his land grab in Ukraine for the circle to be complete.
"The West needs to be hardheaded in its assessment of the risks involved in doing business with Russia over Syria and firm about the limits of any cooperation. Islamist terrorism is a major threat and has the capacity to cause death and suffering on a huge scale. It must be dealt with as a matter of urgent priority. Yet the greatest long-term threats to a peaceful and liberal world order remain Russian terrorism and the determination of a revanchist Kremlin to impose a new sphere of influence and systematically try to destabilize its neighborhood, not only in Ukraine but also in the Caucasus, the Baltic States, Poland and the Balkans. The civilized world must defeat terrorism, not selectively but in all forms and on all fronts," Turchynov wrote.