President Trump will be in Europe this week to meet with world leaders — allies and adversaries alike — to discuss pivotal agenda items for American, NATO, and global stability interests. He will start off Wednesday and Thursday at the NATO summit in Brussels, Belgium.

In a few tweets, the president telegraphed his objectives for the overseas trip:

The president is right to press NATO members to boost their defense spending. Only five NATO members (the United States, United Kingdom, Estonia, Poland, and Greece) met the two percent threshold in 2017. For years, countries like Germany, Spain, Italy, Canada, and others have not even come close to meeting their obligations to the collective defense alliance. Worse, quite a few NATO allies — especially Germany — appear to have no interest in even developing a plan to get to two percent. The German government says it has a plan to get to 1.5 percent by the middle of the next decade, but the plan’s incredibly slow, incremental changes do not satisfy calls for serious change.

On top of that, President Trump is said to be reassessing the U.S. military presence in Germany, where some 35,000 active duty soldiers are currently stationed. Poland, which is meeting its NATO commitments, has offered $2 billion for a permanent U.S. military base. Warsaw says that the plan could help NATO by deterring further Russian aggression in Eastern Europe.

Germany has increasingly become a thorn in the side of American foreign policy and trade objectives in the 21st century. From Berlin’s unserious approach to NATO to Chancellor Angela Merkel’s cozying up to Vladimir Putin and the terrorist regime in Iran, all eyes will be on how President Trump deals with Germany’s reluctance to re-evaluate its policy initiatives. Additionally, the president has often taken issue with Germany’s trade protectionism, which has resulted in a massive trade imbalance of $64 billion in Germany’s favor.

Many of the same nations that failed to contribute more to the collective defense agreement have simultaneously grown their respective social welfare and migration programs. Their refusal to cut entitlements and benefits, while taking advantage of the umbrella of U.S. protection, has signaled to President Trump that many of our NATO allies are not serious about meeting their obligations.

Last month, the president fired off several letters to NATO member nations that have failed to live up to the two percent threshold, warning them if nothing changes, the U.S. would have to act accordingly.

One such letter to Germany read in part:

“The United States continues to devote more resources to the defense of Europe when the Continent’s economy, including Germany’s, are doing well and security challenges abound. This is no longer sustainable for us.”

While Germany may bear the brunt of critiques, President Trump has come to Brussels promising to end the existing state of affairs at NATO, which he perceives as a situation that places an unfair burden on the U.S. both economically and militarily. The United States under President Trump is a proud member of NATO, but if certain European powers fail to get on board with their obligations, they may find a partner in Washington that instead prioritizes reciprocal trade and alliance-building measures with countries that are true to their word and live up to their commitments.