In two weeks, the countries of the European Union and their eastern European friends will gather in Brussels for the fifth Eastern Partnership summit.
It could become a landmark event, heralding a new strategic vision for this EU initiative for years to come.
The environment has changed drastically since 2009, when the policy was launched. The masks are off. The Eastern Partnership has an open and bitter adversary - Russia.
That adversary has realised the tremendous potential of the Eastern Partnership project to challenge its revanchist interests.
Russia became seized by the transformative impact of EU soft power on its neighbours and grew fearful about its implications for the authoritarian regime in Moscow.
No surprise that today each Eastern European partner and many EU member states suffer from direct or hybrid Russian aggression in response.
There is no time for hesitation, appeasement, half steps or wait-and-see policies.
We have to be more ambitious, not low profile. Passionate, not technocratic. Be brave enough to call a spade a spade, an aggressor an aggressor.
One shouldn't allow European values to fade away when Russia comes dangling lucrative gas contracts. Hiding behind current challenges or the low ambitions of other eastern partners is easy. But it is also escapism, and one cannot escape reality in the end.
Ukraine learned this lesson the hard way.
We are not just a European state but that European state which has paid the highest price for its legitimate aspirations.
We are a European nation that has progressed in leaps and bounds on difficult political and economic reforms at a time when we have also had to counter external aggression by Russia's sophisticated armed forces.
Four years ago, the whole of Ukraine was counting down, with a fainting heart, to the signature of the EU association treaty at the Eastern Partnership summit in Vilnius.
That treaty symbolised their dreams of a better life in a united Europe. That passion turned into the Revolution of Dignity on the Maidan after the decision of the former Ukraine leader not to sign.
It resulted in full-scale Russian aggression in Crimea and hybrid war in the Donbas region in east Ukraine, where I come from.
Over the four past years, millions of Ukrainians have stood up courageously to this deadly threat, some on the frontline and others in the rear, under the EU flag of common values. More than 10,000 Ukrainians have paid with their lives for our European choice.
Can one find another example of such sacrifice for those very things that the EU flag is supposed to represent?
So came the awakening of Ukraine - a new Ukraine with a vibrant civil society, solid political momentum for change, and, most importantly, with redoubled dedication to European ideals and principles.
Ukraine has always been a front-runner on the European agenda in our region.
We are ready to keep shaping a common future and the president of Ukraine has tabled long-term initiatives to deepen the mutually beneficial process of convergence.
We are moving ahead on integration with the EU energy union, the EU digital single market, association with the Schengen free-travel area, and potential integration with the EU customs union.
Our reform ambitions could be made easier by a strategic plan of assistance, based on the model of the European Plan for Ukraine recently presented by Lithuania.
What you fight for is what you stand for. And what you stand for is who you really are.
We Ukrainians don't ask the EU to fight for Europe in Donbas - we can do the fighting. But the EU should at least say clearly what it stands for.
The EU is supposed to stand for the extension of the area of freedom and prosperity, to be a lighthouse for others, to reach out to those who embrace Europe. That would be the EU that we believe in.
What Ukraine ultimately wants is a simple message: "Once you're ready - you're in". Ukraine's task would be to get ready. The EU's task would be to decide if or when Ukraine was ready.
This would mean everything to us, and cost nothing to the EU.
It would be an honest and just step of historic proportions that would breather new oxygen into European unity. It would be a clear demonstration that the EU really is a stronghold of democracy, freedom, and dignity.
Kostiantyn Yelisieiev is an aide to Ukrainian president Petro Poroshenko and Ukraine's former ambassador to the EU