Bridge construction between North Korea and Russia has been underway since late April, but recent construction activity has been sluggish. Notably, on the Russian side, the bridge construction method was abruptly changed from the steel pipe pile method to the cofferdam method. This is a traditional approach in which part of the river is dammed off to build a section of the bridge, then the remaining portion is dammed off to construct the rest. The cofferdam method is typically used in North Korea for small-scale bridge projects. It is possible that Russia’s adoption of this construction method was based on the judgment, following an on-site survey, that the shallow water depth would allow the work to be carried out more easily and at lower cost. However, considering that work barges and large pile drivers have been observed since May, it appears to be part of a cost-cutting measure. In that case, where is the 91 million USD that Russia invested now?