Other methods are under study. These include oxidation or biological decontamination of the material into concrete. But many defense analysts want to press on with the two available methods rather than delaying further. America has two incinerators and plans on building seven more. Russia plans to build incinerators as well.
Many ethical questions arise on the topic of chemical and biological weapon manufacturing.
But also, questions arise on the funding of these projects. The military claims the research is used for defense, but there is no clear distinction on what it is really used for at all. It is not an arguement to stop further new, potentially beneficial research. As dangerous as chemical and biological warfare is, countries are worried that these weapons will fall into the wrong hands. The 1972 Biological Weapons Convention bans the development of places to test such weapons, but the USA has built large maximum containment facilities and admits to having 31,000 tons of chemical agents.