Considering the current state of the effort it’s hard not to take a serious look at the Russian solution. There’s always a bit of ego and history involved in the US-Russian relationship but scientists are scientists and if they say they want to help, they probably really want to help. BBC:

Standing on a barge that transports the two subs after their submersion, the Mir-2 captain underlined that the subs were probably the only deep-sea vessels in the world capable of stopping the leak.

“Our subs are unique. There are two of them and they can submerge and work simultaneously. Also, they are powerful enough to work with any other additional equipment.

“There are only four vessels in the world that can go down to 6,000m – the Mirs, French Nautile and Japanese Shinkai. The Mirs are known to be the best, and we have a very experienced team of specialists,” he said.

But Mr Chernyaev added that such an operation would have a chance of succeeding only if BP or the US government asked the Russian government to join efforts to stop the leak.