Nuclear Weapons

Proportionate decommissioning is an option for dealing with Nukes.  In other words, if Iran has 10 nukes, and the US has 10,000, they would get rid of 1 for every 1,000 we get rid of.  In that way, no one country has to be the the first to be 'unarmed', and in 5-10 years they could have a ceremony where every country destroyed their last unit together.  Why the heck not?