Ukraine-NATO relations

Polish Prime Minister Donald Tusk has sharply criticised Karol Nawrocki, a candidate in the second round of Poland’s presidential election, for declaring his refusal to support Ukraine’s accession to NATO should the Alliance approve it.

Karol Nawrocki, who is backed by the Law and Justice (PiS) party, made the remarks during a broadcast hosted by Sławomir Mentzen, a former far-right presidential candidate. Tusk characterised Nawrocki’s position as “state treason”, arguing it undermines a long-standing bipartisan consensus in Polish foreign policy.

In the interview, Nawrocki stated that he would not sign a ratification bill allowing Ukraine to join the North Atlantic Treaty Organisation, even if other NATO members reached agreement on the matter. The statement was made during an appearance on Mentzen’s online programme, in which the far-right figure has been inviting second-round candidates to commit to a set of demands in exchange for political endorsement from his voter base.

Tusk, leader of the Civic Platform (PO) and Poland’s head of government since late 2023, responded with strong condemnation. “Support for Ukraine’s Euro-Atlantic integration has always transcended party lines,” Tusk said. “Presidents from across the political spectrum, from Lech Kaczyński to Andrzej Duda, have recognised the strategic necessity of Ukraine in NATO.”

Historically, successive Polish administrations—regardless of party affiliation—have promoted NATO enlargement to include Ukraine. Lech Kaczyński, the late PiS president, was a vocal proponent of this during his tenure, as was his successor Andrzej Duda, also aligned with PiS. Tusk himself supported this position during his first term as prime minister beginning in 2007.

The underlying rationale, according to Tusk, is Poland’s security calculus: that a non-aligned Ukraine acts as a buffer vulnerable to Russian aggression, whereas a Ukraine integrated into NATO contributes to regional stability and serves as a frontline deterrent against Russian expansionism. With Poland sharing a border with the Russian exclave of Kaliningrad, this is not a theoretical concern.

Nawrocki’s statement, Tusk argued, contradicts not only Poland’s foreign policy tradition but also the national interest. “A Ukraine stranded between Russia and NATO will inevitably face further attacks. When that happens, Poland will be next,” the prime minister said, referring to the risk of conflict spilling over into Polish territory, particularly if the United States—as some fear under Donald Trump’s presidency—reduces its commitment to European defence.

Analysts have noted that Nawrocki’s rejection of Ukraine’s NATO membership appears to be driven by tactical electoral considerations. As he faces the runoff election, the PiS-backed candidate is vying for the support of Mentzen’s electorate, which is characterised by nationalist and isolationist leanings. Recent polling suggests Nawrocki has a viable path to the presidency, but the political cost of aligning with Mentzen’s anti-Ukraine stance may prove significant.

Critics point out that Nawrocki’s stance not only marks a departure from traditional PiS policy, but also risks legitimising pro-Kremlin narratives. Blocking Ukraine’s accession to NATO is a long-standing objective of Russian foreign policy. As such, Tusk and others argue, Nawrocki’s refusal to endorse Ukrainian membership plays into Moscow’s hands.

The prospect of such a pivot from PiS-aligned leadership has unsettled observers both in Poland and abroad. It signals, some argue, a broader shift in segments of Polish society and politics towards appeasement of Moscow, driven by fear of war and a desire to avoid confrontation with Russia. That sentiment, Tusk suggested, risks reversing the hard-earned security architecture Poland has built since the Cold War.

Nawrocki, a historian by training, has been accused of ignoring key lessons of Poland’s 20th-century experience. “Every attempt to appease imperial Russia has ended in disaster for Poland,” Tusk remarked. “From the Molotov-Ribbentrop Pact to the Warsaw Pact, compromise with Moscow has never guaranteed peace—only subjugation.”

Despite Tusk’s denunciation, Andrzej Duda, Poland’s incumbent president, continues to back Nawrocki’s candidacy. This has prompted further questions about internal coherence within PiS on the issue of Ukraine and NATO.

Tusk warned that undercutting Poland’s commitment to Ukraine’s Euro-Atlantic trajectory not only betrays a strategic consensus but may also embolden further aggression by the Kremlin. “Before the Russian soldier sets foot on Polish soil, the signal has already been sent—Poland can be divided, persuaded, or ignored,” he said.

In his final remarks, the prime minister cautioned that gestures of accommodation towards Vladimir Putin, whether from Mentzen or Nawrocki, constitute a betrayal not just of Ukraine, but of the Polish people’s own aspirations for peace, sovereignty, and European security.