An interceptor designed for missile defense was ordered to be launched by Robert Gates personally and used to hit a dying U.S. spy satellite:hydrazine (N2H4, derived from NH3 but similar to H2O) has been ruptured. We will know today. Don't pick the debris.
If true, and even if not quite true, it shows how real and useful the technology behind the missile defense system can be, even for peaceful purposes - in this case, it is useful to protect the U.S. spying know-how against wise guys elsewhere.
I think it is a good idea for the U.S. or the democratic world to build such a system. At the same moment, it is also clear that some countries that are effectively weakened by such a system may feel a kind of dissatisfaction.
The missile defense system has been criticized by arguments that I have always considered completely bizarre - for example by the comment that it can't be 100% reliable so it is useless and won't change any decisions. Well, nothing in the real world is 100% reliable so the people whose decisions are only influenced by 100% reliable gadgets and information and who are only impressed by 100% success are clearly detached from the real world completely.
In the process of evolution of life much like in the process of development of new technologies, the initial versions of organs or devices were less reliable and less efficient and they could be improved later, by incremental additions and adjustments. The missile defense system would follow the path that has been tested millions of times.
And that's the memo.