First, for the first time since the end of the Cold War in Europe in the last century, the US has deployed long-range missiles in Europe. These US long-range missiles can be launched from Germany to targets deep within Russian territory, reaching both the capital Moscow and the city of St. Petersburg in Russia. They are capable of carrying nuclear warheads even though they are currently intended to be used as conventional weapons.
In essence, the US deployment of these long-range missiles in Europe violates the disarmament agreement (Intermediate-Range Nuclear Forces Treaty - INF) that the US signed with the Soviet Union back in 1987. In 2019, US President Donald Trump unilaterally terminated the INF, so now the current US President Joe Biden faces no difficulty in redeploying long-range missiles in Europe.
Second, this is a bilateral agreement between the US and Germany, not a collective decision by NATO. The US and Germany chose this approach to avoid the issue being seen as a matter between NATO and Russia, to prevent internal disagreements within NATO, while still achieving the political, psychological, and military effects of a common NATO policy.
Third, along with the US and Germany's announcement of the deployment of long-range missiles in Germany, Germany, together with France and Poland, announced that they have agreed to cooperate in developing long-range missiles so that they no longer have to rely on US long-range missiles. In this way, NATO members in Europe emphasize that the US redeployment of long-range missiles in Europe is only a temporary solution, making it difficult for Trump, should he return to power in the US, to oppose and reverse it.
Biden wants to reassure European allies while these allies bind the US more closely to its commitment to ensuring security for allies in Europe. And all of this is aimed at warning, deterring, and countering Russia.
