Relations between neighbours Russia and Ukraine have been strained this week over Russian President Vladimir Putin's threat to target missiles at Ukraine if it joins Nato and signs up to the US missile defence shield.
The two were also locked in a dispute over gas which threatened to disrupt supplies - the third such row in only two years. Here readers from Russia and Ukraine react to a tense week in the region.
DMITRI VYSOTSKI, MOSCOW, RUSSIA
People should stop accusing Russia of being in the wrong here.
Every country must protect its own national interests and President Putin is reacting to the threat posed by Ukraine's Nato membership and the US missile defence shield.
No-one in Russia wants to see their country become weak or unable to defend its population from whoever wants to play puppet with them.
It's also only natural for Russia to desire to rebuild its strength and powerful position by any means available.
I am critical of some of the government's policies but I support Mr Putin on this issue.
Normally when I come into work in the morning I discuss the big political issues with my colleagues. This morning people were not worried about this issue going any further.
Mr Putin spoke of missiles being pointed at Ukraine, but it is simply a case of strong words being exchanged, nothing more. There are too many close ties between the countries for any such threat to be carried out.
Ukraine also added to the tension by becoming more in debt to Russia in its gas purchases.
ANDRIY HUNDER, KIEV, UKRAINE
For nearly 20 years Ukraine has been an independent state, something that is still very difficult for Moscow to swallow.
Russia must accept that it is no longer a superpower.
Mr Putin's threat to turn missiles against Ukraine once again underlines Russia's use of scaremongering with the intent to dominate its neighbours.
As soon as Ukraine made the decision to become a member of Nato, Russia resumed its game of blackmail, threatening to switch off the gas during a freezing winter.
Ukrainians made their choice during the Orange Revolution declaring that they want to change the way of life for their children.
Moscow must learn to respect Ukraine's decision to become a democratic European country, a member of Nato and, eventually, the EU.
Ukraine's entry into Nato will guarantee its independence from further Russian meddling and will protect EU states from the threat of Russian blackmail to cut off the gas.
The people of Ukraine want to be a part of a free Europe, and not a chunk of an old and derelict Soviet Union. Time to let go, Mr Putin.
SERGEI, DONETSK, EASTERN UKRAINE
President Putin is absolutely right in his response to Ukraine's actions.
Encircling Russia with small missile systems now will lead to larger missile installations over a wider area in the future.
The threat follows Russia's warning of a new global arms race
Most wars in the past were started as a result of small provocations.
Ukraine's president Viktor Yushchenko is anti-Russian and many of us Ukrainians can't stand him - he has only 14% of popular support.
Russia will be forced to point missiles at Ukraine if it joins this herd of Nato poodles loyal to the US, along with Poland and the Czech Republic.
I wish the USA would just focus its efforts elsewhere.
SASHA CHEREVKO, DNIPROPETROVSK, UKRAINE
As a Ukrainian who was born in the USSR, I support Viktor Yushchenko and Yulia Tymoshenko in their attempt to forge closer ties with the West.
These leaders have given me hope.
I do not want to be constantly manipulated and misinformed by political leaders, like Mr Putin, who use groundless fears and threats, all because of our desire to join Nato.
I've travelled to Europe and have seen how people live there and how the rule of law is respected.
I don't think the Russian people particularly care about us or the people of Poland or the Czech Republic.
I also don't think Russia sees us as an enemy, but its leaders insist on preventing us from moving towards EU and Nato membership.
Our right to go our own way and make our own decisions must be respected.