The kingdom’s de facto leader, Crown Prince Mohammed bin Salman, was once shunned in diplomatic circles. Now he is playing an important role in negotiations over Gaza and Ukraine.

Saudi Arabia's crown prince wasn't in the room for the first high-level talks between Russia and the United States over Moscow's war on Ukraine on Tuesday, but Mohammed bin Salman still won the day for hosting the gathering that could be a game-changer in the bloody conflict.

As President Donald Trump presses ahead with his attempt to end the war in Ukraine, he is leaning on an old ally: Saudi Arabia’s powerful Crown Prince Mohammed bin Salman, whose success in mediating an end to the conflict could deepen his already warm ties to the new American president.