Pro-Russian soldiers march outside an Ukrainian military base in Perevalne, Crimea, Thursday, March 20, 2014. With thousands of Ukrainian soldiers and sailors trapped on military bases, surrounded by heavily armed Russian forces and pro-Russia militia, the Kiev government said it was drawing up plans to evacuate its outnumbered troops from Crimea back to the mainland and would seek U.N. support to turn the peninsula into a demilitarized zone.(AP Photo/Vadim Ghirda) (Vadim Ghirda/AP)

Andrii Deshchytsia is foreign minister of Ukraine.

So, the unthinkable happened: Within a couple of weeks, Vladimir Putin pulled off his blitzkrieg. Russia’s “anschluss” of Crimea heralds a new international reality. To a standing ovation of his parliament on Tuesday, the victorious Russian president signed a treaty decreeing Crimea’s accession to the Russian Federation.

Recent events have dealt Europe and the global security system their heaviest blows since the rise of the Berlin Wall. Whether they are ultimately knocked down depends on the world’s reaction. But the adage that “that which doesn’t kill us makes us stronger” is applicable here.

Ukraine is ready to stand its ground. Crimea is Ukrainian. We have the law and the truth on our side. We won’t budge in the face of aggression. We will take Russia to the courts and use every venue available to make clear that this is not the way to behave in today’s world. And Ukraine has plenty of reasons to count on international solidarity.

The whole world stands with Ukraine these days — but this is about more than unanimity. What’s happening is also about steadfastness. Russia is trying to drive a wedge between members of the international community. The Russian doctrine that Putin presented to a clapping Kremlin audience on Tuesday was about one thing: drawing new lines of “legitimate interests” that justify wars and annexations. But the world has seen this already. It is nothing new. It is history repeating as a farce.

The time for diplomatic platitudes is over. Today’s Russia is a threat. Today’s Ukraine is the new frontier to all people of good will. Being a European democracy is Ukraine’s free and sincere choice. Many people have paid for this with their lives. Ukraine is the new place to stand — if you care about democracy, freedom and human rights.

The world has been confronted with an unexpected challenge. But this problem might become an opportunity. There is a new, positive drive in Eastern Europe. Ukraine started it by trying to shrug off its old sins and become a better state. Our choice is not about Russia but about being a functioning, future-oriented European democracy. We will stick to this, and we will succeed.

Once Ukraine succeeds, it will represent a viable democratic alternative to many interested onlookers in the post-Soviet space. The European Union can find in Ukraine a new drive. The United States can find here a “long game” it is destined to win. And the rest of the world will sleep better at night knowing that the new international reality doesn’t depend of the whims of ever more Hitler impersonators.