From Commander Bradden, Starfleet Intelligence:
The Cardassians are a warlike and xenophobic people. Once they ruled a far reaching star empire with an iron fist, dominating the various native populations they conquered. They were a fierce military force. However, they are now a people barely surviving. Their ill-fated alliance with Dominion forces during the Dominion War resulted in near total destruction to the Cardassian homeworld and decimated their population. The Detapa Council, a civilian, democratic organization, came into power following the Dominion War, and has attempted to rebuild both the agriculture of the planet and the economy. Unfortunately, the council has faced considerable opposition from a group known as the True Way.
The True Way aims to return to the military order. While the Detapa Council leads Cardassia, and, indeed, the Cardassian Union, the True Way has a large and impassioned following. Quite regrettably, Cardassians have a history of turning to a strictly regimented military in times of trouble. Their homeworld has never been plentiful, resulting in a period of famine in their early history. To resolve the lack of natural resources on Cardassia Prime, the military decided to expand outward and appropriate the resources of other planets and peoples. They treated subjugated peoples as slave labor, regularly committing atrocities against the native populations. For that matter, the military government spied upon and, by many accounts, tortured their own citizens using an intelligence organization known as the Obsidian Order*.
Most unfortunately, this has limited the amount of aid that the Federation has been able to offer the Cardassians. The Federation has, naturally, made an attempt to assist in reconstruction efforts. The Andak Project, lead by Federation botanist Keiko O'Brien, is one of the few such attempts the Cardassians have allowed. The Andak project has provided agricultural assistance in rehabilitating Cardassia Prime's depleted food resources. However, there is far more work to do to rebuild the planet.
It is worth noting that while the Cardassians have engendered animosity in numerous other species, the conflict between Bajorans and Cardassians is particularly bitter due to the brutal Cardassian Occupation of Bajor from 2328 to 2369.
*It is worth noting that the Obsidian Order seemed to be an equivalent institution to the Romulan Tal Shiar. However, the Obsidian Order was supposedly destroyed by the military government in 2371. My sources indicate that one of the current leaders of the Detapa Council is actually a former Obsidian Order operative.
From Commander Korak, Klingon Intelligence:
The Cardassians are worthy opponents in battle. They are fierce warriors and fight with honor.
We fought, and defeated, them in the Dominion War. The Dominion suckered them, the poor bastards. They had no chance once they allied with those honorless targs.
Now, the Cardassians are trying to rebuild their empire on a lifeless ball of rock. It would be a miracle if they succeeded, after the Dominion bombarded their planet at the end of the war. They rebelled against the Dominion at the end, which helped us. Distract the enemy, leave them open to attack! Yes, the Cardassians were useful. Misguided at times, but useful.
We shall see if they regain their military might, though I doubt it. I doubt it greatly. Their leading council now is far more concerned with agriculture and kowtowing to the Federation. Pah! Although rumor does say that Gul Madred is leading a potential military force known as the True Way. These next few years should be interesting for the Cardassians, if they don't die out first.