Russia decided that due to “tensions” between the US that it was no longer “possible” to adhere to deal to reduce weapons-grade plutonium.
Admittedly, the US has failed to reduce its weapons-grade plutonium noting that its facility to convert this material has been delayed and over budget. During this time Russia has been unilaterally adhering to the deal so it is not surprise that given the state of affairs between the US and Russia that it would stop adhering to a bilateral deal that the US was not adhering to in the first place.
