The EUISS is an agency of the European Union
"If [Trump] believes Europe must give in on something—for example, on trade or defence spending—he could decide to withdraw troops," says Giuseppe Spatafora to El Español.
"But recently, his administration has shown more interest in emphasising that the US will not leave Europe. The same is true with Ukraine: it could suspend aid if it deems Ukraine an obstacle to peace. But it has recently taken a tougher stance with Putin." (in Spanish)