Divided Europe: What if Trump Doesn't Support Europe in Case of a Russian Attack? 

If Donald Trump wins the elections and becomes president again, he will likely pursue a policy of disinterest in NATO and not support Europe in case of a Russian attack. This could leave Europe alone and without an effective guarantee of military protection.

In this scenario, Russia could feel more confident in attacking Europe, as it would not have to face a significant military response from the United States. NATO, without US support, would not be able to provide an effective defense against Russia's military and atomic force.

Furthermore, Trump has been known for his "every country for itself" approach and his refusal to commit military and economic resources to international conflicts. This could lead Europe to face a critical challenge in terms of security, as it would not have an effective guarantee of military protection and would have to rely on its own armed forces for defense.

In this sense, the scenario of a Russian attack on Europe without US support is probably a possibility that Europe must consider and prepare for.