(CNN) President Donald Trump is in the middle of his 9-day foreign trip, a stretch defined thus far by its smoothness and general lack of controversy.

Trump navigated the early days of the trip through the Middle East with no major problems, a considerable feat given the delicate politics of the region and Trump's much-proven tendency to pop off. He landed in Italy Tuesday and will meet with Pope Francis today. The media coverage, and again this is a big shift for Trump, has been largely positive since he touched down in Saudi Arabia on Saturday.

In short: It's been the best six days of his presidency in quite some time.

Which, you might think, could provide not only momentum for Trump's off-track presidency but also offer up a blueprint for how Trump can succeed when he return stateside this weekend.

You'd think wrong.

Why? Because there are several factors present on this foreign trip that simply can't be replicated on a day-to-day basis when Trump is roaming the White House.

First, this trip -- Trump's first venture outside the United States since being elected president -- was meticulously planned for months.

"We put a lot of time and thought and planning into what we were going to do and how we were going to do it," explained a senior administration official speaking without attribution as Air Force One jetted to Rome on Tuesday night. "Trips like this don't just come together."

That's absolutely true. But the sort of time and planning dedicated to this trip, which was literally months in the works, is impossible when you are talking about the daily grind of Washington life.

Think about it this way: Your 40th birthday is six months away. You plan and plan for it. The party, as a result of all that planning, goes smoothly and everyone has fun. Could you plan and execute another party the next day? And the day after that? And every day for the next four years?

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Second, and related, is that the long-term planning for the trip allowed Trump advisers to create an almost-totally controlled environment with very little free time for Trump.

In a terrific piece for Politico on Trump's trip so far, Annie Karni wrote

"A decision was made early on to visit a part of the world where Trump is venerated and feared, and to pack his schedule so that he mostly stayed on message and, according to one aide, 'didn't have time to tweet.'"

Since arriving in Saudi Arabia on Saturday, Trump has sent just seven total tweets. (He has also retweeted First Lady Melania Trump and Israeli Prime Minister Benjamin Netanyahu.) That's well below his normal pace. And, the seven tweets Trump has sent are the sort of cookie-cutter stuff you see from the average politician -- a speech he gave, a picture here and there and absolutely nothing even remotely controversial.

Trump is also surrounded -- at almost all times -- by the people he trusts and listens to the most: Melania, as well as his daughter, Ivanka, and her husband Jared Kushner. Trump does best -- and has through his entire adult life -- when he is surrounded by the cocoon of his family.

But, trips end. And that sort of tightly controlled environment with his family all around him is really hard to make happen back in Washington. Yes, Ivanka lives in DC now. But she isn't by her dad's side at every second. Ditto Melania, who hasn't yet moved into the White House. Which means that Trump, when he returns to Washington, will also return to the isolation -- watching cable TV, tweeting, nursing grievances -- that have made his first 125-ish days in the White House so problematic.

Finally, what Trump is doing on this foreign trip is being, well, Trump. The dirty little secret of foreign trips is that the accomplishments and deals are all worked out in advance. What the President does in these settings is smile for the camera, shake a bunch of hands and give short speeches touting how important the relationship is between America and fill-in-the-blank country.

This is exactly the sort of thing Trump has spent the last few decades of his life doing. He excels as the public face, the salesman, the cheerleader for a brand. For years, the brand he was selling was Trump. Now the brand he is selling is America.

The duties of a president while in Washington are far more complicated. Rather than photo-ops and heavily-scheduled public appearances, Trump has to construct a policy agenda and work with Congress to pass it -- not to mention deal with the ongoing Russia investigations.

To be clear: Trump's success (so far) on his foreign trip is worthy of praise. What it isn't, however, is a guaranteed sign of things to come. If Trump is going to turn his presidency around, it will be by figuring out how to effectively govern (and live) in Washington. And you can't learn that in Rome.