The phrase "an unsustainable path" is correct and usable in written English.
You can use it when discussing practices, policies, or behaviors that cannot be maintained over time without causing negative consequences.
Example: "The company's reliance on fossil fuels is leading them down an unsustainable path that could harm the environment."
Alternatives: "a nonviable route" or "an untenable course".
"They see that we are on an unsustainable path".
Republicanism — as many insiders admit — is on an unsustainable path.
"We are on an unsustainable path," says Peter Orszag, Mr. Obama's budget director.
It is on an unsustainable path and heading towards a serious collapse.
The Work and Pensions Secretary said the law was driving government policy to reduce child poverty on an "unsustainable" path.
Our world is on an unsustainable path that threatens not only our environment, but our economies and our security.
"Despite the policy-induced slowdown in activity, Chinese property remains on a wildly unsustainable path," Mark Williams, an economist at Capital Economics, wrote in a research note.
Mr Osborne said: "This country faces a very simple choice…We can either carry on on a completely unsustainable path or we can continue to reform welfare so that work pays and we give a fair deal to those on welfare and indeed a fair deal to the people, the taxpayers of this country, who pay for it".
Unless entitlement programmes are cut too, or taxes raised to unprecedented levels, or both, the country is on a financially unsustainable path over the next half-century.
John Weaver, a Republican strategist who worked on the presidential campaigns of Senator John McCain and Jon M. Huntsman Jr., has long argued that the party's reliance on the votes of older white men was putting it on a demographically unsustainable path.
He then laid out his reasoning for why the state is on a "fundamentally unsustainable path," pointing his finger at the "policies and the politics mostly coming out of Springfield [which are] really at the core of the problem".
