The US is more reliable than the Russian as far as Kurdish people concerned. Russian betrayed Kurds in Iran after Iran offered them oil deals in 1946. The US supported Kurds in Syria despite Turkey and Saudi Arabia pressure. ISIS Islamic Sunni Arab terrorist forces attacked Kurdish people with the help of Turkey, Saudi Arabia, Qatar, Jordan, and Barzani of Kurds. ISIS Islamic terrorist committed genocide against Yazidi Kurds while alliance above went on supporting them. The US in critical time helped Kurdish self defence.
Today Russian, Iranian, Hezbollah of Lebanon, and Turkey are helping President Bashar al-Assad's government survive while calling on Syrian Kurds to negotiate with the Syrian regime for the peaceful settlement.
Russian business with Iran, Syria, Iraq, and Turkey are growing rapidly; it means only one thing, that Russian is ready to sell out Kurds for business benefit.
The US government is in need for business benefit too, but not betrayed Barzani when he wanted to hold the referendum with help of Turkey and Israel. The US secretary of State Rex W. Tillerson wrote the letter to Barzani before the referendum, which offered the US help in writing. The offer promised U.S. and U.N. support for a one-year dialogue between the Kurds and the government in Baghdad to address a number of outstanding issues that have roiled that relationship in recent years. The ally does that in critical time but Massoud Barzani rejected the US offer.
Russia did not offer President of Mahabad Kurdish republic anything in 1946.
Also, KCK of Kurds (Parliament of Kurds) are not depending on any power in the world for Kurdish people's protection but they are seeking the reliable ally in the world too. The US needs the reliable ally in the Middle East for mutual benefit. YPG and YPJ provided the US such alliances. It is up to the US government performance from now on.
Russia calls on Kurdish parties to negotiate with Syrian regime
Syrian Foreign Minister Walid Muallem said the government could discuss the Kurdish demand once Islamic State is defeated
Kurds ready to negotiate with Syrian government 'to save blood of Syrians'
Tillerson Letters Show U.S. Nearly Averted Kurdish Referendumhttps://www.bloomberg.com/view/articles/2017-10-13/tillerson-letters-show-u-s-nearly-averted-kurdish-referendum