I hear you Wahaay .
Surely , as you say ,Obama had covered these countries without Mr Trump in his handling of this sending wrong signals to the world.
It seems Mr Trump is more concerned with (pleasing) his base rather than governing sensibly for America ?
I am old nuff to remember and to worry that each generation seems to {adopt a bogeyman} be it Jews,Commies, and now Islam?.
{bogeymen } fear appeals to illogical and alternative fact reasoning = dangerous.
In him visiting Uk = grand = visit away = I think Mrs May in her Brexit rush is flailing about a bit .
If you think the maintenance of cordial relations between the leader of the most powerful country on earth without whom NATO would collapse and a country responsible for a million jobs as the largest single investor in the US is flailing about then I don't think you have a very firm grasp on international relations.
It's why Enda Kenny would be right to laugh at suggestions from low-grade Irish politicians that he should somehow snub Trump.