<p>Well, actually, gsp<em>silicon</em>valley, the situation you described about employers reneging on offers does happen, and far more often than we'd like to believe.</p>
<p>The truth is, most states in the US are 'at-will' states which means that a company can release you at any time for any reason, or for no reason, and with no notice (and conversely, an employee can quit at any time for any reason, or no reason, and with no notice). And certainly if you're talking about an international job, then the company is bound to only respect whatever laws hold for the jurisdiction that the job is in, and those laws are often times few and far between. Hence, companies are well within their legal rights to rescind offers even before they start. They might have to pay you the severance package that was stipulated in their offer (as if they had laid you off), but they are otherwise free to do what they like.</p>
<p>To give you an example, when oil prices crashed in the 80's certain oil companies which shall remain unnamed started rescinding signed job offers. So students who had signed their offer and were all ready to start their job were told that they no longer had jobs, and there was nothing they could do. Most of these students had other offers that they had turned down because they thought they were going to go to that oil company. Those other companies had filled their positions, so these people couldn't go back and reactivate their old offers. So they ended up with no jobs at all. And, sadly, they had no legal recourse. </p>
<p>I'll give you another example. During the economic downturn of the early 2000's,. many consulting firms began rescinding signed offers. However, to their credit, they did it in a few more respectable manner than those oil companies did. They basically asked for volunteers with signed offers to either bow out (in return for a fairly decent cash settlement), or to start their jobs on a later date than what their offer letter said, in return for a payment. For example, they might say that instead of starting your job this year, we'll pay you, say, $5000 to start next year. They usually ended up getting enough volunteers such that they didn't have to outright rescind too many offers. </p>
<p>But the point is, companies can, for the most part, rescind their offers anytime they want, and there really isn't a whole lot you can do about it. It just becomes a matter of corporate reputation. In the case of those oil companies, they got an extremely rep for their dodgy hiring practices, such that many college career services offices simply refused to bring them back onto campus. The attitude was that since these companies were not behaving ethically towards the students, the colleges would deny recruiting access to future students. So it just gets down to the ethical reputation of the company for treating employees well. Some companies have excellent reputations for being desirable places to work. Others have terrible reputations. That includes some very famous companies that nonetheless have extremely unethical reputations. You want to avoid those companies that have bad reputations, because they tend to have bad reputations for a reason. </p>
<p>In fact, I strongly remember, years later, one of the executives at one of these oil companies talking about how when oil prices crashed again in the late 90's, this time they had "learned their lesson" and were now honoring every single job offer they put out and that is signed by the candidate, and I was thinking to myself "Uh, aren't you supposed to honor every signed job offer you make? That's just like the old Chris Rock joke of how irresponsible people go around trying to take credit for doing things that they're supposed to be doing anyway. You're bragging about how you honor every signed offer, well, you're SUPPOSED to be honoring every single job offer." Or so I thought. Then I found out that this is not true, and that companies backtrack on offers all the time.</p>