The United States has long complained about allied contributions to its security partnerships. Every U.S. government has sought to recalibrate alliance burden sharing. Traditionally, Washington has sought more money from those partners, but in recent years the request has increasingly been for the ally to do more for the alliance, to take on more roles, capabilities and missions. The Japan-U.S. alliance over the last two decades has been a case study in this evolution.
No matter how contentious this process has been — and it has been very difficult at times — there has always been a mutual respect for both parties and for the institutions — the alliances — that are being discussed. There has been an understanding that while conditions have changed, these security partnerships benefit both countries, and that with some adjustments, they can and will continue to be relevant and mutually beneficial.
U.S. President Donald Trump is said to want to pursue a "cost plus 50 percent" formula for alliance financing; if so, he is rejecting the foundational premises of those partnerships. According to this proposal, host governments would pay all costs for stationing U.S. troops on their territory, along with an additional 50 percent. This formula would disregard all "in-kind" payments that other governments had made to support the U.S. presence, such as donations of land or construction, or taxes or duties that are foregone.