2016 is a year of anniversaries for Ukraine, not all joyous: April marked the 30 years since the Chernobyl nuclear disaster, and September marks the 75th anniversary of the Nazi massacre at Babi Yar. It has been two years since Russia launched its surreptitious invasion of Eastern Ukraine. It is also the 25th anniversary of the failed Soviet coup of August 1991, an event that precipitated independence movements in Ukraine, Georgia, Armenia, and the Baltics, but passed without much ceremony in Moscow last week.

Wednesday also marked the 25th anniversary of Ukraine’s declaration of independence from the Soviet Union, when the country’s border with Russia became an international boundary. Last year’s independence day festivities were marred by bloody clashes between Ukrainian and separatist forces in the east. A recent uptick in fighting has stoked fears that the same will be true of this year’s commemoration, especially after the Kremlin announced a new round of war games in the Black Sea earlier this month. “We have to walk through the 25th year of independence as if we are on thin ice. We should understand: The slightest misstep can be fatal,” Ukraine’s President Petro Poroshenko warned on this date last year. This week alone, at least nine people are said to have been killed in fighting. On its hard-won independence day, Ukraine finds its self-determination under attack.

Two years of war have revised its national borders and narrative, and Russia’s expansionist project threatens to further fracture an already divided land. A quarter-century of independence has not enabled Ukraine to fully escape Russian control. So Ukrainians could be forgiven for wondering how, exactly, to celebrate this bittersweet day.

In an address in Kiev on Wednesday, Poroshenko attempted to provide an answer. A military parade down the city’s central boulevard displayed the Ukrainian army’s might, “created almost from scratch,” since 2014, he said. “This is a signal to the enemy: The Ukrainians are ready to seriously continue to fight for their independence.”

That fight has been smoldering, in one form or another, for most of Ukraine’s history. The nation was on “thin ice” long before Russia’s imperial project threw the region’s borders into “constant flux,” as Ukrainian historian Serhiy Bilenky writes in his history of nationalism in Eastern Europe. This was a period when Ukrainian writers had begun formulating an idea of their nation as a distinct entity, one that shared a historical and linguistic connection with its neighbors but was markedly distinct. “The mental maps of Ukrainians in the 1830s–1840s did not necessarily reject Russian visions of both Russia and Ukraine. Ukrainian and Russian geographies were to a large extent compatible,” Bilenky writes. “The Ukrainian gaze, however, emphasized an ethnically split empire rather than a national space dominated by Great Russians.”