It's based upon a policy brief that was written by Dr. Sumantra Maitra in February 2023 for the Trump-affiliated Center for Renewing America. Titled "Pivoting the US Away from Europe to a Dormant NATO", it details how the US can get the EU to defend Europe while the US focuses on containing China in Asia.

The gist is that the US would pull funding from non-essential NATO activities that have nothing to do with defending the bloc from a Russian attack, which Maitra believes isn't realistic anyhow owing to a lack of will and capability, thus enabling it to return to its core mission and reduce bureaucratic bloat. Everyone would be pressured to ramp up military spending in order to remain under the US' nuclear umbrella, but sub-bloc coalitions would take responsibility for defending the eastern flank, not the US.

Maitra's proposal is aimed at ending the era of European freeloading by abruptly shifting the burden for continental defense onto their shoulders, with the US then transforming into an "offshore balancer" vis-à-vis Eurasia (mostly with respect to China and Russia) and "a logistics provider of last resort" for the EU. As part of this transition, the EU would develop cross-border defense industries instead of retaining its purely national ones so as to improve interoperability, thus facilitating the US' aforesaid logistics role.

As regards Politico's piece, which builds upon Maitra's policy brief in the ways that were just explained, Trump 2.0 would also reportedly halt NATO expansion while entertaining the idea of freezing the NATO-Russian proxy war along the Line of Contact. In principle, this approach would meet some of Russia's security guarantee requests, thus possibly creating grounds for a pragmatic compromise. Suffice to say, Ukraine wouldn't be allowed to join NATO, though it would still maintain military ties with the West.

Although the Biden Administration is controlled by liberal-globalists who believe that the US should continue letting the EU freeload off of it as a reward for their ideological alignment, military-strategic imperatives vis-a-vis China have already prompted the Pentagon to partially implement Trump's plan. This has taken the form of promoting the rapid resumption of Germany's military leadership in the EU via the "Fortress Europe" project, which the two preceding hyperlinked analyses describe at length.