Former CIA director David Petraeus said Russian President Vladimir Putin's "efforts to make Russia great again" by invading Ukraine had "backfired." 

The retired US army general made the comments in a wide-ranging interview with DW.

He said Russia's army had "underachieved in virtually every conceivable area" since the war began on February 24.

"For starters, they did not have a competent campaign plan. They attacked in five or six different locations. Their logistics proved absolutely abysmal. The level of training of their soldiers and their junior leaders is clearly inadequate," he said.

After failing to capture any of Ukraine's major cities, Moscow was forced to pullback from territory around Kyiv and refocus on the separatist regions in the east. Although much of the southern strategic port of Mariupol is under Russian control, a last pocket of resistance has been holding out inside the city's Azovstal steel plant.

NATO could get bigger

In the wake of the invasion, the US, EU states and other countries have imposed sanctions on Moscow and boosted investment in defense.

Sweden and Finland are considering joining NATO, which would take the military alliance to 32 members. They are expected to make a decision this month.

"Another consequence of Putin's effort to make Russia great again … has backfired and is serving to make NATO great again," Petraeus said, with the alliance having looked under considerable strain during Donald Trump's presidency.

Moscow has warned of "serious consequences" and that it could deploy nuclear weapons in the European exclave of Kaliningrad if Sweden and Finland decide to sign up.

"You have to be concerned that there could be some response," from Russia, Petraeus said. "But I think, number one, those are very competent forces ... They worked for me in Afghanistan. They were very competent, very professional, very well equipped... And they worked very well with the international forces."

Germany took 'extraordinary' decisions

After the start of the war, German Chancellor Olaf Scholz announced €100 billion ($105 billion) in funding for the underfunded Bundeswehr and committed to raise military spending to above 2% of GDP.

"Let me just note how extraordinary the decisions taken by still a relatively new chancellor and new government have been," Petraeus said, calling Germany's one-off Bundeswehr payment a "very wise commitment."

He also said Berlin's decision "to provide lethal military supplies and weapon systems to another country for the first time in Germany's post-World War two history" was "very, very significant."  

Petraeus was in command of the largest NATO mission Germany has ever participated in in Afghanistan. He was also a senior military or intelligence figure within multiple US administrations that had been trying, only with very moderate success, to encourage Germany to increase its military spending and consider a more active military role in the 21st century.

Germany, which has faced criticism for being slow to support Kyiv with arms, last week approved the sending of heavy weapons to Ukraine. It is considering sending howitzers in addition to the Gepard anti-aircraft tanks and other equipment it has already agreed to send.

What is Moscow planning for May 9?

Petraeus also addressed predictions that Moscow may be planning to declare a victory or expand the war on May 9, a major Russian holiday that marks the Soviet Union's triumph over Nazi Germany. 

"There are reports that the Russians, at the very least, are considering some kind of general mobilization announcement where this would transform the country from conducting a 'special military operation,' as they have termed it, to conducting World War III or something along those lines to try to galvanize Russian popular support," Petraeus said. 

He added that it was unlikely Putin was planning to use nuclear or chemical weapons on that date "because crossing those thresholds would be so significant." 

Petraeus also voiced doubts about a theory that Russia might use May 9 to target Ukrainian President Volodymyr Zelenskyy: "There are credible reports of saboteurs, of spies, of special operators who have been in Kyiv and have, it seems, tried to target President Zelenskyy... you can never take anything off the table when it comes to Vladimir Putin... But again, I don't think that is very high in likelihood." 

The UN says it has recorded 6,600 civilian casualties in the war so far, including 3,200 deaths, warning that the real figures are likely to be considerably higher. The West has accused Russia of committing war crimes, a charge Moscow denies.  

When asked whether the West should support truce negotiations with Putin after accusing him of atrocities, Petraeus said that should be for Ukraine's leadership to decide. 

"We should take our lead from President Zelenskyy, and if he and his people are willing to negotiate, then clearly I think it is time that we would certainly collaborate with him on that," he said. "After all, it is his country that is bearing the destructive power of Russia."

He also said it was important to keep in mind that "Vladimir Putin most wants to negotiate," not necessarily because of Russian military losses on the battlefield, but in the hope of "relief from the sanctions on his economy, financial system, inner circle, and the toll that's taking on the business community." 

The interview was conducted by DW's Ines Pohl in Washington.

Edited by: Mark Hallam.