This isn't limited to leafleting, although it did include leafleting. In 1954, the CIA waged a campaign of psychological warfare through radio, leafleting, and political postering on the Guatemalan people in order to scare the army into staging a coup. The attempt was successful, despite the fact that the actual land forces of CIA-backed Castillo Armas were small and barring a miracle, would have been defeated by the forces of the Guatemalan government at the time.

Some background: in 1944, the dictator of Guatemala, Jorge Ubico, was overthrown after a decade and a half of rule, and replaced by Guatemala's first democracy. Guatemala's second president, Jacobo Arbenz, initiated a campaign of land reform known as Decree 900 to take and redistribute a portion of the unused land of the United Fruit Company. At this time, the UFC owned 70% of arable land in Guatemala, its only port, and its only railroad. The plan was to give the appropriated land to poor peasants in order to create a basis for economic growth in Guatemala. Under Ubico, the UFC had been paying property taxes based on an undervaluation of their property. Arbenz's government would have compensated the UFC at this valuation.

The UFC was predictably not happy with this and initiated a campaign with the US government to overthrow Arbenz, on the basis that it was increasing the Communist foothold in South America. The Arbenz government had interacted with the USSR but was not reliant on them and did not align with them. Numerous times they stated that this redistributive policy was only intended to create a basis for capitalist development in their nation.

From Foreign Minister Guillermo Toriello at the Inter-American Conference:

"The delegation of Guatemala is here, its head high, to express the legitimate aspirations of our people and the Revolutionary Government, solidly united in the desire and the effort to achieve an effective political and economic freedom, through the exercise of democracy, absolute respect for the political and social rights of man, and the development of an economic program in accordance with the present and future needs of the nation." http://dspace.cai.sg.inter.edu/xmlui/bitstream/handle/123456789/12884/B45c005d002.pdf?sequence=2

The whole document is worth checking out. In campaigning the government, the UFC hired publicist Edward Bernays to use his connections in US media to paint a picture of Guatemala as fostering communist development. The Dulles family had close connections to the UFC, being large shareholders in the company, while one was Secretary of Defense* (John Foster Dulles) and the other (Allen Dulles) director of the CIA. They participated in lobbying the government to do something about Jacobo Arbenz.

The CIA threw their weight behind Castillo Armas, and initiated their plan of psychological warfare. Armas invaded with CIA assistance in 1954, with only a force of 480 men. They invaded in such a way as to create the impression among the populace of insurmountable odds for the Guatemalan military. Throughout this invasion, the CIA-sponsored radio station Voice of Liberation broadcast news of a popular right-wing insurgency and the inevitable collapse of the Arbenz government. They dropped leaflets and spread rumors of the inevitable collapse of the Arbenz government, as well as using military force to create the illusion of an imminent invasion. To make a much longer story short, this struck fear into the hearts of the officer corps of the Guatemalan Army, and Arbenz decided that this made his continued existence as president untenable. He resigned in June 1954, and was replaced by the dictator Castillo Armas, who repealed Decree 900 and protected the landholdings of the United Fruit Company.

Source: much of this information came from Bitter Fruit: The Story of the American Coup in Guatemala by Stephen Kinzer and Stephen Schlesinger.

I am very open to alternate viewpoints or any challenge to the information I've provided here.

Edit: typo and grammar

*Edit2: /u/Youarenotagangster pointed out that John Foster Dulles was the Secretary of State, not the Secretary of Defense.

I apologize for adding on another question, but is there any evidence that the 'Tokyo Rose' propaganda during WWII caused any significant amount of US military personnel to desert, defect or surrender?

I don't know if it counts as strictly "propaganda" but I can speak to an experience during conventional war. During World War II, the Office of Strategic Services Morale Operations Branch infiltrated leaflets by air and through partisan groups purporting to come from General Kesselring (in charge of German troops in Italy). The air dropped leaflets weren't scattered over enemy troops, but dropped behind the lines to be placed in areas where German soldiers would find them. The contents of the letter stated that it was Kesselring's opinion (again as if written by him) that the Nazi party was simply destroying the German Army in a form of national suicide and that German troops should hand themselves over to the Allies. The OSS discovered the effect of the infiltrated leaflets through interrogation of PoWs who had surrendered and who had read the "Kesselring letter." It is difficult to determine if the letter actually caused them to surrender, but many PoWs mentioned its existence. It can be stated with at least some degree of certainty that it helped induce at least a large enough number of troops to surrender or was at least a believable enough communique, that the General Kesselring found it necessary to deny authorship of the proclamation.

National Archives II (NARA) (College Park) Record Group 226, Entry 99, Box 35, Folder 1 *edit: forgot RG earlier, whoops; also, the actual translated intercepted denial can be found within the folder, as well as the weekly pouch summary pointing to the individual MO Branch report on the event. (many OSS documents do not contain true headers or titles but are parts of memos/communiques/reports)

No discussion of airborne leaflets is complete without Desert Storm. That conflict saw the most effective use of leaflets as a means to inducing enemy surrender. This is the most famous leaflet of the conflict, in which Iraqi soldiers were promised food and hospitality in return for surrender.

This is a report from the 4th Psychological Operations Group that compiles the leaflets it dropped during Desert Storm. There were about a dozen different themes and nearly 100 designs.

In Feburary 1991, over 87,000 Iraqi troops surrendered, and 44% of the Iraqi military deserted. According to a report of the U.S. Army War College (pdf download):

The use of leaflets in combination with combat operations proved particularly effective. Of a targeted audience of 300,000 Iraqi troops, an estimated ninety-eight percent were exposed to the 79 million leaflets dropped in the theater. Many of the 87,000 Iraqis who surrendered were found clutching leaflets or hiding them in their uniforms at the time of surrender. Debriefings of EPWs by the 13th PSYOP Battalion indicated leaflets were effective in influencing Iraqis to abandon their equipment and surrender to coalition forces. Additionally, an Iraqi Brigadier General, captured by the British on February 27th, was quoted as saying "Second to the allied bombing campaign, PSYOP leaflets were the highest threat to the morale of the troops."

In Appraisal of Gulf War Propaganda, R.G. Auckland writes that:

According to Western reports in the field, the Allied aerial leaflets were very much welcomed by Iraqi soldiers and eagerly sought after...Surrender Passes were carried by nearly all those surrendering without fighting, or were surrounded and captured. Pictures were taken by photo-journalists of Iraqi soldiers waving or holding Safe Conduct pieces of paper.

Interesting side note - this article appeals in the “The Falling Leaf: The Quarterly Journal of the PsyWar Society”. The connection between falling leaves and airborne leaflets have been explicit since the start in WWII, as I discuss in this other comment.

One noteworthy series of leaflets were aimed not to induce surrender, but to confuse the Iraqi military about the nature of the invasion. A series of leaflets such as this example all pushed the theme of naval invasion. When U.S. forces overran Iraqi positions, they found that the strategic maps in Iraqi command centers were set up with an emphasis on a naval invasion. Here is an example of such an Iraqi command center from the archives of the 4th POG.

There were several factors that led to the success of American surrender/desertion leaflets. First and foremost, the vast majority of the Iraqi army consisted of conscripts who were poorly supplied, poorly led, and poorly informed. The average Iraqi soldier was completely isolated from any media or information. Moreover, the enormous success of the first 48 hours of air strikes showed many Iraqis that the scenes depicted in leaflets like this were accurate. They quickly understood that the best chance for survival was to abandon their equipment. Also, compared to propaganda from earlier conflicts, the leaflets were culturally aware. The PsyOp divisions were fanatical in their pursuit of cultural adjustments. From the U.S. Army War College report, linked above:

Adjustments made in this way proved culturally enlightening as well as effective for PSYOP personnel. For example, red ink had been used in the initial design of some early leaflets. Pre-testing revealed that red in the Iraqi culture signaled danger and should be avoided. The 8th PSYOP Battalion switched to other colors, as appropriate, for subsequent products. Another set of leaflets had depicted a clean-shaven coalition soldier gesturing affably to an Iraqi. PSYOP teams found that a chin with no beard did not convey as positive a signal as did one with a beard, which signified Muslim holiness and trust to many Iraqis. Later leaflets portrayed coalition soldiers with beards unless they were western (US) soldiers. A particularly successful leaflet depicted Iraqi and coalition soldiers sharing Islamic hospitality over a bowl of fruit. Bananas were added to the design after pre-testing revealed that bananas were a delicacy for Iraqis.

So it can be argued that the promise of bananas in this leaflet was the most effective deployment of written psychological warfare.

I wanted to mention a type of leaflet that while arguably ineffectual from a tactical standpoint, did at least have a lasting impact in the field of weirdness: The leaf-leaflet – a leaflet printed in the shape of a leaf, as if it just fell from a tree.

First, check out this insanely creepy German leaf-leaflet. The text is an ominous poem, with an equally ominous skull for good measure:

AUTUMN

The leaves fall.

We fall like them.

The leaves fall because God wills it,

but we fall because the English will it.

In the coming spring,

nobody will remember the dead leaves

any more than the dead soldiers.

Life will pass on over our graves.

Here is another super creepy example. This one reads:

I fell out of the tree, oh Churchill!

Where are you? Where are your soliders?

Here is another example. It reads:

The leaves are falling.

The promised final victory fails to appear.

Now you might think this is all some idiosyncratic thing unique to the German invasion of France. After all, what better way to communicate with the French solider than with surrealistic poetry printed on a leaf. But oddly enough, America dropped nearly identical leaf-leaflets on Japan, as you can see if this rather beautiful example.

Also, for anyone interested in more reading on this topic, check out this copy of USAF Psychological Operations 1990-2003, by Dr. Daniel L. Haulman, USAF Historical Research Agency.

This has some really good stuff on the nuances of airborne leaflet strategy, including the necessity of cutting off alternative media, the selection of targets, type of aircraft, messaging, illiteracy concerns, etc.