In 2014 at the beginning of the Conflict Russia-Ukraine, The United States impose sanctions on Russia. None citizen of Russia could use their credit cards or debit cards (Mastercard and Visa) The Russian economy was strangled for the time that happened. The Russian wanted to have another way to use their money and have other currency instead of the dollar to trade internationally… the answer… make their own debit and credit cards and use Bitcoin.
In 2016 The United States made other Sanctions this time against Venezuela, all the Accounts in dollars in Venezuela were blocked and the people can not do any more international transactions and even the Citibank close their doors in Venezuela. Once again the people desperate to have a form of trading with other countries started to invest into Bitcoin.
This year not too long ago The United States banned Iran from the SWIFT system now the Iranians cannot use their dollars for international trade and they are investing millions into bitcoins and other cryptocurrencies.
Even North Korea a country that has many sanctions from U.S.A it is beginning to show interest in bitcoins and other cryptocurrencies
Conclusion: Every time that the United States makes an Economic sanction of that kind against a country, it is weakening the dollar and helping bitcoin to grown… No wonder that Russia and Venezuela are in the top 5 countries that have the highest volume of bitcoins. And in a short time, I am sure that we will see Iran rising at least in the top 10
In the next image, the red arrow shows the time of the sanction in Russia and we can see that after 2014 the bitcoin volume starts to grow
In this graphic, we can see that immediately after the sanctions in Venezuela, the bitcoin volume grows
In the case of Iran's sanction is to soon to tell but it will surely follow the same pattern
Sources:
https://docs.google.com/spreadsheets/d/1CKdE7v2w_cJooY3DhdTJzWfzhA_LQeU1mngLMWvP2j0/edit#gid=0
https://www.washingtonpost.com/world/national-security/us-imposes-new-sanctions-on-russia/2014/04/28/974c579e-ced6-11e3-b812-0c92213941f4_story.html?noredirect=on&utm_term=.30f57fa85bb0
https://www.independent.co.uk/news/world/europe/visa-and-mastercard-enforce-us-sanctions-on-russian-banks-9209976.html
https://www.euractiv.com/section/euro-finance/news/putin-sanctions-visa-master-card/
https://bitcointalk.org/index.php?topic=5073999.0;topicseen
https://www.miamiherald.com/news/nation-world/world/americas/venezuela/article169319977.html
https://www.reuters.com/article/us-venezuela-citibank-idUSKCN0ZS17X
https://coin.dance/volume/localbitcoins