Is identifying a chemical equivalent to be able to produce it?
No, the capability to identify a compound does not imply capability to synthesize that compound. Indeed, "analysis" and "synthesis" represent two branches of chemistry, and many chemists spend years trying to synthesize compounds of known structure.

Modern structure determination relies on roughly two steps. First is separation of sample mixtures into constituent parts, using various forms of chromatography. Next is analysis of chemical composition and bonding patterns using techniques such as IR spectroscopy and nuclear magnetic resonance spectroscopy, as well as mass spectrometry (MS), which weighs molecules (and their destructively ionized fragments) with extraordinary precision and dynamic range.

Advanced MS instruments can analyze very small amounts of collected samples, without special preparation, and at atmospheric pressure. Pure samples are not required for the instruments typically used in forensics and product testing (DART). When a pure sample is desired, one or more separation devices can feed the MS instrument in-line (LC-MS, GC-MS, MS-MS).

MS can measure molecular weight so precisely that the chemical formula can be deduced directly based on the fractional weights of the elements due to varying isotopic abundance. Often, a chemical formula is almost sufficient for unique identification. For example, the NIST Chemical WebBook contains only 4 entries with the same formula as the VX agent, all for VX or nearly identical compounds. The PubChem database contains only 1 (VX itself).

It is also possible to identify compounds using known chemical or physical interactions linked to a readout such as a color change. This principle is used in devices such as home pregnancy tests and lead test kits. The US military even has custom field test kits for some chemical weapons.

It should be noted that compounds introduced into an organism may be identified indirectly via metabolites found in blood or urine, even if the original compound is long gone. Again, VX agent is a suitable example.