Donald Trump seems to have a Germany obsession, the country's biggest newspaper, Bild, said on Thursday. Whether it's the country's refugee policy (Merkel is "ruining Germany," he tweeted in 2015), luxury cars (he told Playboy as long ago as 1990 that he would like to tax them more heavily), or its NATO contributions, the US president has consistently picked on Germany when he needs a foreign power to lash out at.

The latest rock was thrown on Wednesday night, when Trump took to Twitter to repeat his blustering opening tirade before NATO Secretary-General Jens Stoltenberg in Brussels. For the US president, Germany's Nord Stream 2 gas pipeline deal with Russia was at odds with its defense budget, which he thinks is too low.

Defending Merkel

Once Merkel had delivered her own reaction, in the form of a history lesson and her personal history in East Germany, other German government politicians lined up to reject Trump's criticisms. First Foreign Minister Heiko Maas vehemently rejected Trump's description of Germany as a "captive of Russia." Germany was one of the "guarantors of the free world," he told reporters in Brussels. "We're not captives — neither of Russia nor the US."

Meanwhile, Defense Minister Ursula von der Leyen pointed out to US radio station NPR that Trump's assertion that Germany gets 70 percent of its energy from Russia was "simply not true." The actual figure, the German government said, is around 9 percent.

Merkel's coalition partners also circled the wagons. "The accusations of the American president against Germany because of the building of Nord Stream 2 are not objective and immoderate," said Rolf Mützenich, senior MP of the Social Democratic Party (SPD), in a statement. "They simply follow his trade policy instincts."

Mützenich went on to explain patiently why building a new gas pipeline from Russia to Europe made economic sense for Germany, and contrasted Trump's "intimidation attempts" with the more diplomatic approach from Ukraine, whose government has its own concerns about Nord Stream 2.

Read more: Opinion: A NATO summit in Trump's parallel universe

Defense Minister Ursula von der Leyen pointed out the facts to Donald Trump

Germany's former foreign minister, Sigmar Gabriel, also of the SPD, accused Trump of angling for a "regime change" in Berlin.

"America under Trump cannot be relied upon," Gabriel told the Spiegel news magazine. "Trump is giving the North Korean dictator a survival guarantee and wants regime change in Germany at the same time."

He also urged Germany to strengthen its stance and issue "clear, firm, and above all, unified European responses," to Trump.

"We can't stand for this," Gabriel said. "If he demands billions of dollars for US military expenses, then we have to demand the return of billions spent on refugees that were created by failed US military intervention in Iraq."

Strengthening Merkel

It's no secret that Trump and Merkel have a poor personal relationship, but German political analysts don't think she is Trump's real target. "He sees Germany as the entry point to try to crack the European Union," said Josef Janning, head of the Berlin bureau of the European Council on Foreign Relations (ECFR). "Because if you want to crack a pack, you attack the alpha animal."

But even if Trump succeeds in weakening the EU, Janning thinks it is having the opposite effect on Merkel herself – especially in the rift between herself and those on the right of her Christian Democratic Union (CDU), and the domestic forces who would like to see the end of the Merkel era. "Within her own government she is closing the ranks, very clearly," he told DW. "When she is under obviously unfair attack from the outside, that will bring at least the mainstream together behind her."

Janning argued that Trump's stark overstatements, be it on trade, on defense spending or on Russia, might play well with voters supporting the fringes of the German political spectrum, but not with Merkel's own CDU voters – even the more conservative ones.

Undermining the world order

But for other analysts, all this is beside the point. Claudia Major, senior researcher at the German Institute for International and Security Affairs (SWP), thinks the criticism of Germany is just a sideshow. "It's not about Merkel or Russia or energy or pipelines, or any of that," she told DW.

"That's just an excuse for Trump. For him it's about completely undermining the multilateral trans-Atlantic order as we know it. And I think that the scale of the problem we have hasn't yet been realized in Germany. If he valued NATO, and if he felt that its survival was important, he wouldn't act this way."

Read more: Can the trans-Atlantic relationship survive Donald Trump?

Major pointed out that Trump had taken up a different position to most of his European partners on nearly every major international issue, from the Iran nuclear deal and the Paris climate agreement to moving the US embassy in Israel to Jerusalem. "Trump rejects the entire multilateral, rule-based architecture — like NATO, WTO, EU — which is based on solidarity," she said. "What he wants is not alliances but deals."

She also had little optimism about the apparent agreement on Thursday that NATO partners would raise their defense expenditure. "Do you think he's going to be happy with 2 percent?" she asked. "The core function of NATO — as a defensive alliance — has already been enormously undermined by all this bickering. Even if he says now that 2 percent is great — the damage has been done."

"I think he has Germany especially in his sights because Germany stands for everything he thinks is stupid," Major added. "But at the end of the day, Germany is just the hook — it's about much more."