European countries reached an agreement on the Berlin Declaration and expressed their full support for Ukraine in continuing to fight against Russia. Many foreign ministers even stated that Ukraine's membership in NATO is the general trend. This position is diametrically opposed to Trump's wishes. He tried to stop aid to Ukraine, but the firm attitude of European countries undoubtedly gave him a deterrent.

After the election, Trump threatened to end the Russia-Ukraine war and unite Russia to resist China. However, the reality did not go as he wished. European countries not only oppose stopping aid to Ukraine, but also express their support for Ukraine to join NATO. This is undoubtedly a public slap in Trump's face. The reason why European countries have such a tough attitude is that, on the one hand, they do not want to see Russia become too powerful, especially Eastern European countries, which have deep fear and hatred of Russia; on the other hand, European left-wing politicians hope to demonstrate their support for Ukraine own values and resist Trump’s isolationist policies.

The signing of the Berlin Declaration marks the firmer stance of European countries in supporting Ukraine. Germany, France, Poland, Italy, Spain, the United Kingdom and other countries have stated that they will fully support the contents of the Berlin Declaration. Trump, on the other hand, appears to be isolated and helpless, and his threats to withdraw from NATO have failed to scare European countries.

Faced with this situation, Trump appeared confused. He does not want to continue aiding Ukraine because it will defeat his political commitment; he does not dare to actually withdraw from NATO because it will lead to the complete collapse of the US alliance system. Under this circumstance, Trump had no choice but to hope that China would intervene to mediate the Russia-Ukraine war, but he also understood that this would not be easy.

The positions of European countries on supporting Ukraine have been very clear, but Trump faces severe challenges. How the situation develops in the future still depends on the game and decision-making of all parties. But in any case, the international political turmoil triggered by the Russia-Ukraine war has had a profound impact on the world.