Portland International Airport  ?

There are no direct flights from US to the Philippines unless you fly Phillippine Airlines and they dont use Portland International.  If you use PAL to fly non stop from USA to Philippines  you must go through Manila.

NO YOU HAVE TO GO TO L.A. to get there or else you can't go

There are no direct flights.  Some of those destinations require 3 or more stops!  And about half of those destinations cost more than $10,000 at present!

Most of those connect onward in Los Angeles (LAX), Chicago (ORD), or Dallas, Texas (DFW) and currently require 14 days of quarantine.   For Australia refer to https://covid19.homeaffairs.gov.au/travel-restrict...  For Singapore, see https://safetravel.ica.gov.sg/files/SHN-and-swab-s...

Th3ere are no direct flights to any of those places, but you would typically not go through Seattle to get to any of them.

You cannot take a nonstop flight to any of those destinations from PDX.  The list of nonstop destinations from PDX can be found here: https://www.flypdx.com/NonstopDestinations

Nonstop international destinations from Seattle are listed here, although some routes are not currently operating due to COVID: https://www.portseattle.org/page/non-stop-internat...

You can't fly directly to Tehran from anywhere in the US. 

I believe only Los Angeles and San Francisco offer nonstop flights to Melbourne.

There's an easy way to find out. Google to find the PDX website. On the opening page, click on 'departures'. You'll get a list of all departing flights for today, with the destination and airline. You can change the day to see flights for yesterday and tomorrow. Most flights leave daily if they leave at all.

Then there's this website: https://www.flightconnections.com/flights-from-por...

However, I suspect that website is giving pre-covid info. Some of those flights might not be currently running.

With the exception of Iran, you'd have to go through LAX to reach those destinations nonstop. You'd have to go through somewhere like London to connect to Iran as there are no direct flights from the US due to political sanctions