Anxiety seems to be at the root of the modern condition. Besides the stress that we deal with in our private lives, there are always political and geopolitical concerns (like the above) that stress us as well. Given all of this, I actually don't think that anxiety is by any means an irrational response. It's only when our response is disproportionate to the threat or when anxiety starts to take over our lives that it really becomes a problem.
I can honestly say that with each new child that we have added to our family, my own anxiety has increased. After all, I have my family's wellbeing to look after, not just my own. Courage however, is a decision. It's how we respond to anxiety provoking thoughts that we have control over, not the external situation. Let me share with you the 2 best techniques that I use to overcome anxiety.
1. Limit Your Exposure to Unecessary Stressors
As you may have guessed, news is a big unnecessary stressor for me. The philosopher Jaques Ellul wrote about news provoking anxiety in his excellent book Propaganda: The Formation of Men's Attitudes. (Like Assange, Ellul was also worried about an emerging technological dictatorship, even though he was writing in the late 1960s.) On anxiety, he states:
Many studies indicate that fear is one of the strongest and most prevalent feelings in our society. Of course, man has good reasons to be afraid - of Communist subversion, revolution, Fascism, H-bombs, conflict between East and West, unemployment, sickness. On the one hand, the number of dangers is increasing and, because of the news media, man is more aware of them; on the other, religious beliefs, which allowed man to face fear, have disappeared almost entirely. Man is disarmed in the face of the perils threatening him, and is increasingly alarmed by these perils because he keeps reading about them... This largely explains why the dominant fears in our society are 'social" fears, tied to such collective and general phenomena as political situations.
Ellul makes certain to emphasize here that we keep hearing about distant threats because of our overconsumption of news media. Really we are bombarded with information that can potentially upset us many times a day. The appropriate response should be to drastically limit our exposure to this sort of information, or whatever the unnecessary stressors are in our lives.
Rather than ruminating on news or letting various negative thoughts take over, I try to focus on not feeding fears, which brings me to my other tried and true technique for controlling anxiety.
2. Memorize and Repeat Power Phrases That Help You Cope
Ancient philosophy was designed to be memorized, so that it could be “at hand” when we are confronted with tumultuous situations…The teachings of Stoics, Epicureans, Cynics, Pythagoreans, and Platonists were often condensed into short, pithy maxims designed to be easily remembered so that they would pop up in our heads when were are in stressful situations...The students wrote these maxims down in their handbook, memorized them, repeated them to themselves, and carried them around–that’s the point of a handbook, so the teachings are procheiron, or “close at hand.” 
By now I have quite a collection of power phrases memorized and I think these are the best for inspiring courage, preventing rumination, and focusing on the present moment (rather than worrying about future events). If I'm feeling upset I try to internalize these messages rather than feeding fears:
"Be content if the smallest thing goes well." - Marcus Aurelius
"Keep me safe, my God, for in you I take refuge." - Psalm 16:1.
"You don't have to turn this into something. It doesn't have to upset you." - Marcus Aurelius.
"Live as brave men; and if fortune is adverse, front its blows with brave hearts."
"Cling to what is good." - Romans 12:9
"Be happy for this moment. This moment is your life." - Marcus Aurelius
"No passion so effectually robs the mind of all its powers of acting and reasoning as fear." - Edmund Burke
"The art of life is to deal with problems as they arise, rather than destory one's spirit by worrying about them too far in advance." - Robert Harris (speaking as Cicero).
"Courage is the commitment to begin without any guarantee of success." - Johann Wolfgang von Goethe
"No man is free who is not master of himself." - Epictetus
"God is my salvation: I will trust and I will not be afraid." - Isaiah 12:2
"Endure and renounce." - Epictetus
"The joy of life consists in the exercise of one's energies, continual growth, constant change, the enjoyment of every new experience. To stop means simply to die. The eternal mistake of mankind is to set up an attainable ideal." - Aleister Crowley
"Make the best us of what is in your power, and take the rest as it happens." - Epictetus
"Fear is a reaction. Courage is a decision." - Winston Churchill
"Confine Yourself to the present." - Marcus Aurelius
"Spes mea in Deo est." (My hope is in God).
I hope that these are useful to you if you struggle with anxious thoughts like I do!
1. Ellul, J. (1973). Propaganda. The Formation of Men’s Attitudes. 153.
2. Evans, J. (2013). Philosophy for Life and Other Dangerous Situations. 116.
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