Divisions within Germany’s Social Democrats over rearmament and relations with Russia are set to come to a head at a congress starting Friday, as party leader and finance minister Lars Klingbeil faces a backlash from the party’s old guard.
One critic is the eldest son of former SPD chancellor Willy Brandt, whose Ostpolitik of rapprochement with the Soviet Union at the height of the cold war still looms large over the party.
Peter Brandt, a 76-year-old historian, has co-signed an SPD motion criticising the government’s rearmament plans and pushing for a “gradual return to détente and co-operation with Russia”.
“We are a long way from a return to a stable peace and security order in Europe,” reads the Manifesto, which was released ahead of this week’s SPD party conference.
While strengthening defence capabilities in Germany and Europe as a whole was “necessary”, they wrote, the push “must be embedded in a strategy of de-escalation and gradual confidence building — not in a new arms race”.
Peter Brandt told the Financial Times that Klingbeil had signed off on the new defence spending spree “without checking whether it is actually the line of the majority of members”.
“It is a problem. The stance is not as clear among members as it is reflected in the leadership.”

The criticism comes as Klingbeil, who is vice-chancellor in the coalition government led by Christian Democrat Friedrich Merz, prepares a massive injection of funds into the military — with a 70 per cent rise in the country’s defence budget by 2029.
Brandt’s remarks are a reminder that many Social Democrats are still reluctant to embrace the country’s “Zeitenwende” — a historic turning point — on defence, which former SPD chancellor Olaf Scholz declared in the wake of Russia’s full-scale invasion of Ukraine in 2022.
The party rebellion could pose problems for Klingbeil, who negotiated the coalition deal with Merz in the wake of the SPD’s worst electoral result in February.
Dissenters could make it more difficult for the government, which relies on a razor thin majority of 12 seats, to pass legislation on the budget, weapon deliveries and a planned return to conscription.
The rebels “are not a majority in the SPD but they are also not a small minority”, said Uwe Jun, a political scientist at Trier University. “There is a long tradition in the SPD of those who, in the 1970s and 1980s, came from the peace movement. They criticise anything that is to do with the military.”
The debate has intensified as Klingbeil is revamping the party leadership after the election fiasco. The 47-year-old politician has been accused of cementing his power after he replaced Rolf Mützenich, 66, as head of the SPD parliamentary group. Mützenich is one of co-signatories of the Manifesto.
“Personal and political tensions also play a role,” said Gesine Schwan, a political-science professor and longtime SPD member, who was offered the chance to sign the motion but refused.
Klingbeil, who came of age after the fall of the Berlin wall, has sought to shift the party’s foreign policy stance. In a series of speeches and editorials in 2022, he admitted that the party had “failed to recognise that things had long since begun to take a different course” in Russia.
The Manifesto’s signatories say the search for peace should be the priority. Ralf Stegner, who helped pen the text, caused controversy last month when it emerged that he had flown to Azerbaijan in April to meet with Russian officials, including a former prime minister and an official subject to EU sanctions.
Stegner, 65, who then sat on the parliamentary committee overseeing Germany’s intelligence service, has defended the meeting, noting that lawmakers from Merz’s CDU party had also attended it as a way to keep the lines of communications open with Moscow.
“You have to keep talking to everyone,” he told the FT. “Just the insinuation that it means agreeing with what the others say, or that you’re a secret agent for a third party — that is, of course, utter nonsense.”
Stegner’s stance underlines the enduring nostalgia in the SPD for Willy Brandt’s Ostpolitik. Party faithful who joined the SPD under Brandt’s leadership and who are now in their 60s, account for 58 per cent of members, a party insider said.
Peter Brandt, who says he never saw completely eye to eye with his father, said he signed the manifesto because he thinks the Russian threat is overblown.
“I do not share the idea that Russia is going to attack Nato,” he said. “The Russian army has shown weaknesses in the Ukraine war.”
He added that Nato “is now conventionally superior to the Russian army. Even without the Americans”. He also described Nato’s newly adopted goal of spending 5 per cent of GDP on defence as “irrational”.
“The rational approach should be: you do a threat analysis first.”
Klingbeil has countered that Willy Brandt, who won the Nobel Peace Prize in 1971, had also overseen big defence budgets of more than 3.5 per cent of GDP.
“And in the end, I don’t think anyone would associate Willy Brandt . . . with focusing exclusively on military matters,” he said this week.
Klingbeil is emblematic of a “new school of thought within the party,” Jun said. The younger MPs of the SPD are “rather pragmatic” on Russia, he added.
But Schwan said Klingbeil will still have to contend with the old guard for a little longer: “Détente, security and peace policy are still part of the SPD’s DNA.”