Gas can be easily exported from other nations. US has plenty od shale gas and oil which is main reason for falling prices. Another way to replace gas is electricity which can be easily generated from anything that burns.
Calad please for once get your facts straight.
Iran will not and can not replace Russian supply:
http://af.reuters.com/article/energyOilNews/idAFL6N0RZ09820141004
USA will not and can not replace Russian supply:
http://www.zerohedge.com/news/2014-04-20/us-gas-will-never-replace-russian-gas-europe
http://nationalinterest.org/feature/lng-wont-save-europe-10295