Well... yes
Some suppliers use Chinese-sourced nic, some use US sources.
When e-cigs first arrived, the tobacco industry did of course object, and joined the anti groups. That changed about a year ago when an alternative income stream from smokeless tobacco products began to look like a good idea, because it became clearer that cigarettes would eventually be squeezed hard by regulations in order to force usage down.
Since that time, the resistance has been mainly from the pharma industry (who will lose sales of NRTs in a big way), and various anti-smoking groups, who are against any type of tobacco or nicotine (or indeed pleasure?). There is an argument that the anti groups would not exist except for pharma support, but that is another matter. Essentially, BT has stopped its opposition, which most likely means they are planning their own e-cig models - to be introduced as soon as the legal status of the industry has stabilised.
As you imply, the tobacco industry has control of agricultural resources, manufacturing, distribution, and marketing; and as they will need the income stream from e-cigs eventually, they are now in wait-and-see mode. The role of smokeless tobacco products was in a state of flux until recently, but most commentators would say that time has passed, and such products could well be a significant proportion of the industry in the future.
BT is like any major industry - very slow to catch on at first, but realists in the end, as they need to keep the money flowing.