There is no such thing as implicit guarantees. The US has shown it is not a trusted country, and as such, we expect that it will also renege any written guarantees.

> if American business and workers are harvesting minerals then if Russia attacked the USA would have even more incentive to intervene militarily

Or Russia just invades while being careful not to damage their buddy's mines. Maybe the US even helps the Russians out once the Ukranian "dictator" is forced to begin fighting in too close proximity to the minerals.

The point is that Russia won't have to attack any more, because Ukraine will already be nothing more than a puppet state after having been forced to sign the kind of peace deal that Putin wants.

American businesses and workers operate all over the world. No-one thinks that this means that all these countries will receive military support from the US if they are invaded.

Another relevant detail here is that a lot of the resources included in the deal are in territory that's currently occupied by Russia – which Trump clearly envisions Russia keeping in any peace settlement.