I think international conflict and market panic might actually be bullish for the U.S. dollar in the short run.
I do agree long-term there are too many forces working against it though. The amount of dollars that were printed over the last several decades is sizable to say the least. However, most of these dollars are held abroad and in foreign reserves. This is a big reason we haven't seen the level of inflation (or decrease in dollar value) you'd expect with all the money printing and debt issuance the Fed has pursued. International trade will probably rely less on the dollar going forward and inflation will ultimately come home to roost.
While I do expect a decline, I don't expect a collapse, at least relative to other fiat currency, because there is no currency with enough trust to replace it.