Disruption of financial markets is not a precision weapon, and it frequently backfires. Currency wars aligning with multipolar powers makes them even more disruptive. Once the US defense of the dollar turns from theoretical to reality, it necessitates violence. You can say "the USD has all this power as a reserve currency because of US military power projection," and it may be true, but once other powers start to align and actively compete with the dollar as the reserve currency, the US needs to actively respond. And that means making good on their threats, not just projecting them. Thus, global financial instability leads to violence.