The secret to Iranians 40-year resistance against the arrogance?

Give proper attention to God, and “ask Allah of His grace,” [Quran: 4:32] in all your affairs–in personal, political and international aspects–and the Almighty God will answer. When you believe in God’s grace and blessings, its first result is that you feel powerful: you feel strong. Weakness, disappointment and such feelings are fleeting: this is so great, so valuable.

Another feeling that will come to you from reliance on God–on His never-ending power, a never-ending blessing–is hope: you will gain a feeling of hope. Hope will grow, and your hearts will glow with the light of hope. When there is hope, trust in God; have self-trust and reliance on God’s power, then a nation will become invincible. A human being becomes an element of never-ending power, movement, and improvement. The secret of so much insistence on reliance on the Almighty and begging from the Almighty in the words of our pure Imams (p.b.u.t), and in Duas, is this. When you rely on God, “O God, those who could save themselves in the face of storms in this material world, some of your power is given to them. So, give us some of it as well.” In this Dua, in Sahifeh Sajjadiah, Imam Sajjad (a.s.) teaches us to pray and beg like this: we are advised to supplicate and be humble [in front of God], not to lose our way, to stay away from mistakes, and not to consider ourselves minuscule and powerless. If you are connected to the never-ending divine source of strength and richness, then you will not need anyone else. “O God, make us heedless of the rich out of your richness, and relieve us from fear of loneliness through your connection.” Even if the whole world turns their backs on you, you will be strong. A small bit of this feeling emerged among the Iranian nation; as a result, we have been standing strong against shameless, impertinent, hegemonic powers of the world for forty years. What we have in this matter is small: the more it grows, the more this strength and ability grow. 

Imam Khamenei, Aug 13, 2018