Know Your Audience

Marshall delivered this speech at Harvard, and his goal was to convince them first. He opens with an appeal to their intelligence in the very second sentence:

"That must be apparent to all intelligent people." (1.2)

Just to be perfectly clear, he's including the people listening. He's not like, "Smart people get this, but not you guys. Hoo-boy, are you dumb." Marshall was making the rhetorical statement knowing anyone listening (especially Harvard students) would say, "Well, I'm smart, so it's apparent to me."

The speech itself is specific, but not overly so. He's prescribing a series of basic actions, but this isn't a unilateral thing. In fact, the one thing he is extremely specific about is the fact that they can't do much of anything without Europe's support:

"It would be neither fitting nor efficacious for this Government to undertake to draw up unilaterally a program designed to place Europe on its feet economically." (7.2)

He's right. It's a good thing to help, but it's a better thing to first listen to what kind of help is needed and then do that.

Since this was a short speech designed to unveil a larger policy, he didn't need to get too specific. If he went into minutiae, it's likely his audience would have nodded off. That's pretty much the worst thing to happen during a speech. (Okay, not the worst. The worst thing is always a bear attack.)

Marshall was known as a political moderate in his time, despite the fact that he basically announced socialism for all of Europe. For this reason, he's clear to point out that he has no political agenda for the plan:

"Furthermore, governments, political parties or groups which seek to perpetuate human misery in order to profit therefrom politically or otherwise will encounter the opposition of the United States." (6.9)

Though the Marshall Plan did have a specific enemy: communism and through that the Soviet Union, Marshall was careful not to point it out in the speech. People would get it, and plausible deniability is always an asset. After all, he's not after communism. He's after people perpetuating misery.

Marshall closes with:

"With foresight, and a willingness on the part of our people to face up to the vast responsibility which history has clearly placed upon our country, the difficulties I have outlined can and will be overcome." (8.3)

This is an appeal to American Exceptionalism; the idea that the USA's unique history and culture makes it better but also gives it certain responsibilities.

It's a good way to rile up the folks he's going to need: the intellectual and economic leaders coming out of Harvard.