国債デフォルトは怖くない

米国にデフォルトの前例がないとは神話にすぎない。たとえば（1971年の）ニクソンショック。外国政府に対しドルと金の交換を拒否し、インフレで価値の薄まったドルの紙切れで過去の債務を払えるようにした。
While it is still popular to claim that the United States has never defaulted on its debt, this is a myth. The US has been forced to default a couple of times throughout history, the last of which being when Richard Nixon’s closed the gold window. By cutting the ability of foreign governments to redeem US dollars for gold, America was allowed to pay back past debt with devalued fiat money.
https://mises.org/blog/course-us-government-will-default-its-debt

社会保障のうたい文句によれば、国民は保険料を払えば給付を受けられる。しかし米政府は数十年の間、あからさまなデフォルトを避けようと、給付の条件を変更し続けてきた。この長期にわたるじわじわとしたデフォルトは、今後も続きそうだ。
Social Security has long been sold to the public on the notion that what a worker will receive back is what he or she pays into the system. For decades, however, the government has been changing the terms of this “agreement” as part of an effort to avoid outright default. This long, slow method of piecemeal default, however, is likely to continue.
https://mises.org/library/social-security-long-slow-default

国債は他の債券と何も変わらない。魔法も神秘もない。破綻した企業は年中、債務を再編している。聖なる国債は未来永劫「リスクフリー」でなければならぬという考えは、経済学ではなく宗教にみえる。
Treasuries are bonds just like any other bonds. There’s nothing magic, mythical, or sacred about them...Bankrupt firms, like bankrupt families, restructure their debt obligations all the time. The notion of T-bills as sacred relics to be once and forever “risk-free” seems more like religion than economics to me.
https://mises.org/library/there-life-after-default-0

1840年代にデフォルトした米国の州は、過去の負債を完済することで金融市場に復帰できた。さらに驚くことに、（デフォルトした８州のうち）２州は返済を一部拒んだにもかかわらず、残りの負債をしばらく返しただけで、市場に復帰できた。
States that defaulted temporarily were able to regain access to the credit market by settling their old debts. More surprisingly, two states that repudiated a part of their debt were able to regain access to capital markets after servicing the remainder of their debt for a time.
http://www.jstor.org/stable/2118266

米ミシシッピ州がデフォルトした1840年当時、外国向け債務をデフォルトした国は侵略の危険にさらされた。政府間借入に関する文献では、そのような侵略や侵略の脅しを「砲艦外交」と呼ぶ。
Back then, nations that defaulted on their international debts put themselves at the risk of invasion. In the sovereign debt-repayment literature, such invasions, and threats to invade, are called gunboat diplomacy.
https://mises.org/library/debt-and-repudiation-mississippi