That may be just the beginning of Russia’s growing presence. In addition, Iran is worried that Syria will fall to Syrian rebels backed by Saudi Arabia, Tehran’s enduring rival in the region, and so has extended a $1 billion credit line to Assad’s regime to help it import critical goods and commodities. Iran’s escape from sanctions—and its ability to earn more revenue by producing an additional one million barrels of oil per day by late next year—suggest there’s more where that came from.
I am not able to figure out the meaning of the bold part of above text. Not sure which noun the pronoun "that" represents in the clause. Can you tell me what does exactly Iran’s escape from sanctions suggest?