Under those assumptions the war is no longer “NATO versus Russia.” It is a limited conventional war between Russia (with Iranian and Chinese help in the background) and a U.S.-less, Turkey-less European rump. That is a different conflict. Duration and outcome change more than they did from the missile salvo alone.
What the assumptions actually mean
A secret Trump–Putin understanding that the United States will stay out of a limited UK/EU war, plus a president who will not be removed after a Democratic midterm wave, does three things at once:
The U.S. president, as commander-in-chief, can refuse to send forces, refuse to treat Article 5 as automatic, and slow-roll or block executive-branch implementation.
A Democratic House and Senate seated in January 2027 can still pass money, sanctions, and weapons transfers. They cannot easily order U.S. troops into combat against a president who will not employ them. Aid without U.S. forces, tankers, satellites, and interceptors is not the same as U.S. participation.
European governments would discover in real time that the American security guarantee is a political choice, not a machine. That is the core of Russia’s stated goal: NATO stops being a military threat because the piece that makes it a threat—the United States—does not show up.
Contempt for European leaders is not required for this logic. The operational fact is non-participation.
Military balance without the United States and Turkey
Europe still has France and the UK as independent nuclear powers, capable air forces, and growing ammunition plants. It does not have, on short notice:
Most of NATO’s aerial refueling, strategic lift, and space-based ISR
The bulk of high-end ballistic-missile interceptors and the production surge behind them
U.S. Navy and long-range conventional strike from outside the theater
Turkey’s army, geography, and control of the straits
A secure eastern-flank fuel pipeline system that is still unfinished
Russia does not need to occupy the EU. It needs to keep firing cheaper drones and missiles than Europe can intercept, hit bases and energy, and dare London and Paris to escalate to nuclear use over a “limited” war the United States has defined itself out of. Iran can keep pressure on the Middle East energy system. China can cut rare earths and other critical minerals the same week, which hits European rearmament harder once U.S. stockpiles and airlift are not in the fight.
How long the conventional war would last
With the United States out by prior deal, the campaign is designed to be short and political, not a years-long land war.
PhaseTimeLikely patternOpening blow1 night–2 weeksMass missile/drone raid on UK/EU (and Middle East) targets. Heavy damage to air defenses and fuel. Political shock when Washington does not join.European responseWeeks 2–8UK, France, and others strike back with air and missile forces they control. Interceptor stocks fall fast. No U.S. surge. Turkey closed.Coercive endgameAbout 1–4 monthsRussia offers a settlement: NATO military infrastructure pulled back, no further enlargement, limits on strike systems that can hit Russia, recognition that Article 5 did not bring America. Fighting continues at a lower rate while talks happen.Frozen or formal dealBy 3–9 months in the most likely pathEurope accepts a bad ceasefire or keeps a hollow high-intensity standoff it cannot sustain at U.S. tempo. A long war requires European full mobilization and French/UK willingness to risk nuclear escalation without Washington.
The most likely conventional length under your stack of assumptions is weeks to a few months of intense fighting, then a political settlement inside roughly 3–9 months. That is shorter than the 6–18 month band when the United States was still in the war.
A longer war (a year or more) happens only if Britain and France refuse any deal, spend their independent nuclear deterrent as the backstop, and European industry stays on a war footing after a Chinese mineral cutoff. That is possible. It is not the path a “limited war plus U.S. stay-out deal” is built for. Moscow’s incentive is to stop when NATO is visibly unable to act as one military, not to occupy Berlin.
Limits of the secret-deal premise
A president can keep U.S. forces out. He cannot fully control:
Congress voting weapons and money (weaker than U.S. forces, still not zero)
UK and French decisions on their own nuclear forces
Leaks of a Witkoff–Kushner channel, which would themselves become a political weapon in Europe and in the U.S.
China and Iran widening the war beyond what “limited UK/EU” was supposed to mean
If the deal holds and stays limited, Russia’s objective—NATO ceases to function as a U.S.-backed military threat in Europe—is more achievable than in any previous version of this scenario. The price is that the war’s length is then set by European political endurance and French/British nuclear red lines, not by a race across Germany. That points to a short coercive war, not a long occupation, and not a clean military “win” so much as a political breaking of the alliance as it existed before the first night.