it's that it might be considered by russia to be a provocation and excuse for them to invade. so, the administration has been very, very careful, as have the europeans, to not signal or to not give a provocation that russia could then use as an excuse. whether the sanctions are imposed now or shortly or immediately after an invasion really doesn't make much difference in the impact on russia. other than the provocation issue that i just said. i would expect that the united states congress, when we return on march 1st and 2nd, actually the day before the state of the union, that the congress will take up, the house of representatives and senate will take up in their committees and pass a very, very strong sanction -- list of sanctions against russia that the president can then impose. it may be that the congress would demand they be imposed.