Those groups in Allied countries, especially in this country, who still did not believe in Russo-American cooperation, were brought to a long-lasting silence.I mean, he wasn't completely wrong for the current events of the war. The US and Russia had managed to get along enough to jointly win the war. But the silence of the critics did not last very long. And I think even Opa knew that was a real possibility, but it sounds better to say "long-lasting" than "temporary."
I've been intrigued by the role of countries like Hungary, Turkey, and the like. The book I am reading right now: "Rescue Board" by Rebecca Erbelding (buy it!), tells the story of a government agency that works to rescue refugees of the war. Much of their work happens in these sort of neutral/leaning Allied places. As the Allies are gaining power by their inevitable victory, the neutral countries are more likely to fulfill requests. If a helpful cooperation will lead to some benefit after the war, then why not?
In Opa's article, he talks about the strategic need for Turkey to be on the Allied side, but only when they're ready for it. Turkey is strategic in their location, not only as sort of a place between Allied-occupied territory and Axis-occupied territory, but more about their waterways. The Sea of Marmara with the Dardanelles and Bosphorus strait are essentially the path between the Black Sea and the Aegean Sea (which ultimately leads into the Mediterranean Sea). So essentially, a ship in the Black Sea could pass through the Bosphorus strait near Istanbul, and ultimately find its way all the way to the Atlantic. Here's a map: